Kevin Levin (Classic)

Kevin Ethan Levin, also known as Kevin 11 or Kevin E. Levin is a Human/Osmosian hybrid. He first appeared in the original series and quickly became one of Ben's most notable nemesis. However, he was reformed in Alien Force, and then became one of the main hero characters. However, following the events in "The Forge of Creation", he becomes an insane villian again until his sanity is restored in "Absolute Power Part 2".

Appearance
In the original series, Kevin was a thin and scrawny boy with shoulder-length raven hair, pale skin, and dark brown eyes with black-discolored marks around them (a sign that an Osmosian still has recently absorbed raw energy). He wore a torn black t-shirt, black studded arm bands, brown cargo shorts, gray knee-length boots, and a steel padlock necklace which was a spoil from his first crime: stealing a bike and using it to run away to New York. After absorbing enough energy from the Omnitrix, Kevin becomes able to transform into exact copies of any of Ben Tennyson's original 10 aliens (minus the Omnitrix face). After the collected energy completely overwhelms Kevin's body, he goes through another mutation that is random mixture of body parts from the 10 said aliens which completely destroyed his clothes, except for his cargo shorts.

In Alien Force, Kevin had grown into a tall and muscular young man. His eyes now lack the black marks (as his body fully recovered from and stopped absorbing energy). His normal attire is a tight black t-shirt over a gray long sleeve shirt, blue jeans, and black combat boots. His hair, though still long, is styled into a choppy mullet. Occasionally, he is seen wearing a blue, mechanic's jacket over a white muscle shirt, jeans, and his black combat boots. After he goes through his second mutation, an unbalanced mixture of various matters, the transformation completely destroyed his clothes, except his briefs. As a result, Kevin had to wear an I.D. mask in public to appear human. During Kevin's third mutation, his appearance is again an unbalanced mixture of various aliens that were currently accessible to Ben through his Ultimatix.

Personality
When Kevin was 11 years old, he was a criminally insane sociopath, willing to hurt/kill anyone for his own personal gain and/or pleasure. This behavior and mentality stems not only from being seen and treated as a freak by his peers and family, but also because of the side-effect Osmosians have with absorbing raw energy. His selfishness and sociopath-nature is made apparent when he was once willing to derail a train in the subway and kill countless passengers, only to cash in on the spoils afterward. Kevin had an extremely negative outlook on life because of the countless hardships and struggles he had, feeling insecure about himself as well as having incredibly low self-esteem. He had a deep rooted hatred for other people and society in general, even the innocent as he once said "Nobody's innocent! They just haven't had the chance to make fun of me yet!".

Kevin's outlook changed when he met Kwarrel, a prisoner in the Null Void Prison when Kevin was a fellow prisoner there. Kwarrel was possibly the first person to have been genuinely sympathetic and caring towards Kevin. Becoming somewhat of a mentor and father-figure to him, Kwarrel helped greatly improved his personality. In Alien Force, despite 16-year-old Kevin becoming a con artist and an arms broker, he was more stable, he was somewhat mature but still had a bit of a jock attitude. As time went on and Kevin was accepted by Ben and Gwen, who were his most hated enemies and now best friend and girlfriend respectively, his personality and psyche improved greatly to the point that he became a trustworthy and reliable ally and teammate. His relationship with his friends further contributed to his mental stability as he once told Ben in "Perplexahedron" that he was grateful to them for changing his life. Verdona stated that Kevin's current personality is similar to a younger Max Tennyson's.

While changing for the better, Kevin still sometimes shows a delinquent side, as seen in "Kevin's Big Score", where he attempts to sell the Rust Bucket to Vulkanus for alien technology, albeit technology he intended to give to Ben and conspires with Argit to sell weapons to both sides of a warring race in "Simple". Despite this side of Kevin, Ben and Gwen still show great trust in him.

Though Kevin can still be cynical, insensible, rude, violent, quick-tempered, greedy, and willing to kill; he is a good person at heart and generally doesn't like innocent people getting hurt; most evident in "Andreas' Fault", where Kevin expresses his disgust of how Argit manipulated Andreas and showed no sorrow or gratitude for Andreas's sacrifice, and angrily punching Argit to end their friendship. Kevin also helped rescue Ben's mother when she was kidnapped in "Hit 'Em Where They Live". Kevin, though he is rarely open about it, also has a sensitive side, as seen in The Con of Rath when Jarrett; the ruler of the Pantophage, ate Tiffin. The scene was so shocking to him that he fainted, despite the fact that he is supposed to be the "tough guy" of the group.

While having a more positive outlook on life since meeting Kwarrel and making friends with Ben and Gwen, Kevin still suffers some insecurities as seen when Kevin was mutated once again. In season 3 of Alien Force, when Kevin mutated to become a living colossus composed of the various solid matter, he was visibly disgusted with himself and fluctuated between bouts of uncontrollable aggression and severe depression that almost jeopardized his relationships, especially Gwen. While mutated in Ultimate Alien, he voiced his frustration against Ben the most for being a famous superhero and him "still" being a freak.

Early Life
Kevin Levin was born to Devin Levin and Mrs. Levin. Devin; an Osmosian and a Plumber, was the partner of Max. Sometime after Devin's death, Harvey Hackett came into their lives. Harvey fell in love with Mrs. Levin and married her, thus becoming Kevin's step-father; Kevin was only 4 years old at the time. Kevin wasn't fond of Harvey at the very least, especially since he saw him as a replacement of his real father as well as an obstacle for his mother's love. Harvey tried to be a good father to Kevin, he accepted and raised Kevin as his own, but it was undeniable that he feared Kevin because of his powers, which only worsened their relationship. When he was eleven years old, Kevin absorbed raw energy and demolished their home. This, coupled with the mental instability from absorbing the energy and his initial dislike of Harvey, instilled in him the delusion that Harvey convinced his mother to kick him out in the street (Harvey admitted that he sent Kevin out of the 'house' because he destroyed their home). He then stole a bike. Wearing the padlock around his neck, he ran away and made his way to New York City, where he made his home under the city's abandoned subways.

Ben 10
Kevin was first encountered by Ben in an arcade, where, after befriending him, he was assaulted by bullies and saved by Ben as XLR8. The two attempt to steal video games from a warehouse and got caught by the police, forcing Ben to reveal his powers to him in order to escape. The two subsequently form a partnership to use their respective powers for personal gain; however, when Kevin rigs two trains (one carrying money and one carrying people) to collide, uncaring that the crash would most likely result in the deaths of several hundred people, Ben suffers a crisis of conscience and breaks off their partnership. Ben became Heatblast, wanting Four Arms, to stop Kevin, but to even the odds, Kevin grabbed onto Heatblast and absorbed his energy and DNA, changing him into an incomplete version of Heatblast. When Ben foils Kevin's plans and escapes, Kevin leaves to use his absorbed powers to get revenge on the bullies that tormented him. But Kevin's absorbed powers disappear and he reverts back to his regular form.

When Ben showed up as Four Arms to stop Kevin, Kevin absorbed Four Arms' energy and DNA, changing him into an incomplete version of Four Arms. As Ben and Kevin fight, Ben gains the victory and offers Kevin a new home and a chance to be a good guy. Kevin accepts, but Ben realizes he lied and Kevin tries to take the Omnitrix off of Ben, but feedback from it changes Kevin back to normal and appears to have depleted his powers. He escapes and at the end of the episode reveals he still has Heatblast's powers.

Kevin serves as the main antagonist of the second season. His ability to project heat at the end of "Kevin 11" is a result of the Omnitrix's feedback pulse: the amount of energy it emitted allowed him to fully absorb its powers, giving him access to every alien form Ben had at the time. However, because Kevin's ability to regulate this power is poorer than that of the Omnitrix itself, the energy suppresses his human form and forces him to remain as an alien most of the time. As revealed in Framed, Kevin blamed Ben for this, so he used the powers of the Omnitrix to start a inter-state crime spree in America, both for his own benefit and to damage Ben's (or rather, his alien forms') reputation. Eventually, Kevin's ability to regulate the power fails altogether, causing him to permanently mutate into what Vilgax describes as a "misshapen, chaotic amalgam of creatures from the Omnitrix." Because of this, Kevin fights Ben and as he was about to kill him, Lt. Steel from the Special Alien Capture Team (SACT) shoots him into the water and he is defeated, but at the end of the episode he is revealed to be alive.

After his mutation, Kevin gloats that he has all of Ben's original 10 alien powers plus his own, making him ""Kevin 11"". The known powers he could use include Four Arms's strength, Ripjaws's underwater breathing and steel-bending jaws, Upgrade's stretching, Stinkfly's flight and slime spit, Diamondhead's crystal projections, shape-shifting arm. and immense durability, Heatblast's pyrokinesis, Wildmutt's sense of smell, and XLR8's speed and retains his absorption powers. Despite this, Ben observes that Kevin's powers weren't as strong as their pure forms, exactly 1/10th according to Ben. During his appearance in "Grudge Match", Kevin attacked Ben to get revenge, blaming his condition on him. As the two battled, they were abducted and forced to fight in Slix Vigma's gladiator games. During their battles, Ben helped Kevin to realize the advantages of his mutated form: because Kevin 11 was an amalgam of aliens, he could mix and match their powers to make up for their reduced potency (ex: Diamond Head durability, Four-arms strength, and XLR8 speed equals "one mean punch"). Although forced to work together, Kevin's only goal was killing Ben. After Ben and Kevin succeeded in escaping, Kevin attacked Ben and trapped him against the wall with Stinkfly's toxic saliva before moving in with Diamondhead's spear hand, gloating that no matter what alien Ben transformed into, he knew every one of them. Little did he know that Ben had discovered that there were more aliens in the Omnitrix and had unlocked Cannonbolt, whom he transformed into just as Kevin was about to skewer him before getting into an escape pod. Kevin nearly barged into the pod when he was stopped by Technorg, whom Ben had spared and he declared a life debt to. After Technorg helped Ben escape, he turned his attention to Kevin (who had called him a lap dog just as he was about to kill Ben). The two were transported to a different galaxy at the end of the episode while locked in combat. Technorg defeat Kevin and left the ship to return to his home world while Kevin took the ship as his own (according to the advanced edition of the episode).

Kevin returned in the episode "Back With a Vengeance", where he teamed up with Vilgax to defeat Ben, and eventually managed to remove the Omnitrix with Vilgax's help. However, he betrayed Vilgax later in an attempt to leave both Ben and Vilgax in the Null Void and use the Omnitrix to take over the world, only for Ben to escape and leave him and Vilgax trapped instead. Kevin spent the rest of the series in the Null Void.

A dream version of Kevin appears in "Perfect Day", as a hall monitor of a dream version of Ben's school. In the dream, Kevin was human but then changed into his mutated form (which, with it's Ripjaw's mouth and teeth more pronounced than usual, appeared uglier than it used to be, probably emphasizing of Ben's fear of Kevin) and fought Ben. When Ben took control of the dream, he was then able to defeat the dream version of Kevin in one fell swoop.

Ben 10: Alien Force
Kevin returns in "Alien Force", where he was eventually released from the Null Void (he stated in Darkstar Rising, he did his time for his crimes) returned to his human form, and grows into a tall and muscular young man who has rejoined society and reconciled with his family. He has also become an alien weapons dealer, giving him several contacts with criminals (such as Argit, Vulkanus and Sunder the Retriever) as well as a considerable knowledge in alien tech. He has also learned about his ability to absorb solid matter instead of energy (taught how to do this by Kwarrel).

In his first Alien Force appearance, Kevin attempted to organize a deal between the Forever Knights and the DNAliens in order to sell them level 5 weapons. However, the deal was interrupted by Magister Labrid, Ben and Gwen. Trying to get revenge, Kevin fought Ben, but was easily defeated while the other villains escaped without paying him. Labrid then forced Kevin to help them in finding back the weapon, offering him to avoid problems with the Plumbers then. Though Kevin mainly accepted in order to get his pay, Magister Labrid later sacrificed himself in order to save him from a defective weapon's explosion. This, plus Kevin's interest for Gwen, his promise to Magister Labrid, and his desire to start a better life and become a Plumber like his father, led him to agree to teaming up with Ben and Gwen against the High Breed invasion. It "mostly" served as the reason that he joined the Tennysons in the first place (his promise to Magister Labrid and Gwen could be the other reasons).

Though he initially still felt a little rancorous toward Ben, Kevin slowly reconciled with him, and he proved to be a valuable ally as well as a good friend. Despite his reformation, Kevin still tends to engage in unethical activities: he is not above stealing gold and jewelry from the Forever Knights and Plumbers equipment from Manny Armstrong and Helen Wheels when presented with the opportunity.

In "Darkstar Rising", he reveals that his father was also a Plumber. When younger, his mother told Kevin stories about what his father did. This is a big gap in the original series because in Ben 10, he said that his parents both left him because of his strange powers; this was explained later on in the series as an exaggeration on Kevin's part: Kevin's mother remarried, and in retaliation Kevin destroyed their home which lead to his stepfather causing a huge strain between Kevin and his parents, ultimately making Kevin think they hated him and ran away. At the end of the same episode, Kevin, along with Gwen and Ben became official Plumbers, after which Kevin leaves to tell his mother about his membership, meaning he has/wants to reconcile and rejoin with his family. Also in "Darkstar Rising", when explaining that he wanted to be a Plumber for the sake of being just like his father, it "mostly" served as the reason that he joined the Tennysons in the first place (his promise to Magister Labrid and Gwen being the other reasons). In "Vengeance Of Vilgax" Kevin was subjected to a feedback pulse from the Omnitrix after Ben tampered with it. Because of this, he was unable to revert back to his normal human form, instead becoming a living colossus composed of different matters'. Throughout the season, he was shown to hate what he had become, to the extent of breaking things off with Gwen (much to her dismay), wearing an I.D. Mask in public to appear human, and considering himself a monster. He also discovered that his father Devin Levin, an Osmosian Plumber, was murdered by an alien criminal named Ragnarok, and became bent on vengeance, so much so that he eventually left Ragnarok to his death when he had the chance to save him.

In the series finale "The Final Battle", where Vilgax attempted to separate Ben from his friends, Kevin was kidnapped by Albedo in an attempt to split them up. He was also asked by Ben to back him up when taking on Vilgax, which he did. After Ben's Omnitrix was destroyed, he reverted back to human form, revealing that it was the Omnitrix's power that kept him that way. This is also when Kevin and Gwen share their first on screen kiss.

Ben 10: Alien Swarm
In Ben 10: Alien Swarm, the live-action movie, Kevin is seen driving around with his car. The car is a green 2009 Dodge Challenger. Also he is seen in his human form, with his Season 1-2 clothes and regular absorbing powers. Whenever he absorbs solid objects, his voice sounds distorted. Near the climax he switches to his season 3 clothes revealing that they're a uniform for the garage built on top of a Plumber's base as cover.

Ben 10: Ultimate Alien
Ultimate Alien focuses more on Kevin's past, including how he managed to return to his human form, break out of Incarcecon, and escape the Null Void after the original series, as well as his back story prior to the original series. Kevin still has the ability to change his hands into different weapons even after he returned to normal in Alien Force.

Kevin and Ben no longer share their famous rivalry and instead have become true friends. Kevin acts as an older brother towards Ben. They care genuinely for each other. Kevin is much more open about his feelings, showing gratitude and tries to express it to both Ben and Gwen (mostly Gwen). Gwen and Kevin continue their romantic relationship. He also seemed to have a better connection towards his friends' paternal grandfather, Max Tennyson.

In "Too Hot To Handle", Kevin is able to repair objects in the current matter he has absorbed by releasing a liquid version of that substance and then hardening it again. He can also manipulate whatever matter he is touching by absorbing it and then morphing it into any shape or form he wants. He uses both abilities when he fixed the broken seal of P'andor's suit, morphed it around his body to trap him, and fused the arms together as makeshift handcuffs.

In "Fused", he admits he was selfish when he first met Ben. He also risked his life to save Ben from being taken over by Ra'ad. He also learns that there is another Osmosian named Aggregor. While never explained, Kevin shows sympathy to him because they are of the same race and because Kevin, like Aggregor, was once an insane and violent sociopath due to him having improperly used his powers when he was a child.

In "Ultimate Aggregor", he shows his knack for detective work, and later warned by Professor Paradox to remember who his friends are and that things will get worse before they get better. Kevin explains to Aggregor that the reason that he was a villain in the original series is that when Osmosians absorb raw energy, they become insane.

In "Map of Infinity", Kevin continues to focus on stopping Aggregor (but not more than Ben), Kevin is easily defeated by Aggregor since his powers have increased, Kevin also seemed to know about the Map of Infinity saying it did not exist, the group go in search of the first part of the Map, Kevin wears a Plumbers' Suit, unlike any other Plumbers' Suits, that Kevin had a little white glove and a circle over the glove (which gives access to Ultimatrix of Ben), possibly this glove is for Kevin to use his powers, he proves to be very strong when a giant hammer crushes the group on a wall,he survived and managed to save the group and remove the hammer from the wall.

In "Deep", we see Kevin using a Plumbers' Suit with built-in electrical weapons. His helmet is destroyed, but Gwen uses her powers to make Kevin absorb the matter of his jet, saving him from being crushed by the pressure. However, Kevin still can not breathe, until a Little Fish acts as a "helmet" for him to breathe, in the core Kevin takes the Little Fish from his head (he did not need it since there was air in the core), Kevin also finds and tries to fight Aggregor it to retrieve the second part of Map of Infinity, unfortunately he is easily defeated by the electric powers of Aggregor, Aggregor says that next time Kevin should try absorbing something non conductive, and runs away with the second part of Map of Infinity, leaving Kevin angry. Kevin leaves the Little Fish (who liked Kevin) in Piscciss and is comforted by Gwen at the end, as he seemed to miss the fish.

In "Perplexahedron", When Ben and Kevin get separated from Gwen, Ben says that Gwen can take care of herself and Kevin replies, "That's why I like her." Kevin then talks about his feelings to Ben and how he owes it to them (Ben and Gwen) for putting him on the right path. After finding Gwen (by accident), Kevin tries to say that he likes her, a lot. Then Ben tells her what Kevin's trying to say, and Gwen says, "I know that already." and they kiss, the second kiss in the Gwen/Kevin relationship.

In "The Forge of Creation", as a last resort to stop Aggregor from succeeding in his plans, Kevin absorbs the powers and abilities from the Ultimatrix's unlocked aliens, becoming strong and powerful enough to defeat Aggregor. Unfortunately, this also causes him to mutate and become insane once again as Ultimate Kevin. His old desire for power also returns as he absorbs Aggregor's powers as well. However, Kevin's good heart appears to not be taken over completely, as he accepted 10-year-old Ben's harsh criticism before sparing Aggregor's life, though he declares he will not be so merciful tomorrow.

In "Nor Iron Bars a Cage", it is revealed that back during his time in the Null Void, a prisoner named Kwarrel approached him and offered to help him control his anger and find a purpose, after that he learned how to use its power as shown in Alien Force. Seeing the con as a father figure, Kevin learned how to return to his human form and how he could absorb matter. Kwarrel then showed Kevin a tunnel he had been digging out of the prison to freedom. However, they were ambushed by Morgg who would one day become the warden. Kwarrel held off the guard for Kevin to escape, only to lose his life in the process. Out to avenge his death, even though it went against all that Kwarrel had taught him, Kevin purposely returned to the prison to kill Morgg. He would of succeeded if Gwen didn't save Morgg. Believing that Kevin is truly gone, Ben, much to Gwen's horror, suggests that Kevin must be put down.

In "The Enemy of My Enemy", Kevin went after Argit for all the times he double-crossed him. He first attacked him and sent him towards Ben and Gwen. He later attacked Rust Bucket 3 in order to get Argit, but was forced to retreat due to his car being thrown off the plane. He then attacked the Plumber's Academy and easily took care of the Plumbers. He then attacked and thought he killed Argit (due to Argit closing down his vital systems). During his attempt to kill Argit, he nearly killed Gwen, thinking she betrayed him. However, he restrains himself at the last second and spares her life, saying: "The only reason you're alive is because of what you used to mean to me." before departing, making is clear that a part of Kevin still cares about her and Gwen remaining adamant that they can still bring Kevin back to sanity without killing him.

In Absolute Power, in hopes of trying to save Kevin, Gwen inquires the aid of Darkstar. However, Ben is very furious with the idea. This is Ben and Gwen's last hope of trying to bring Kevin back. Gwen tries to talk to Kevin, who tells her he's been avoiding her because he can't control himself, implying that he doesn't want to hurt her; but he gains the desire to absorb Gwen's powers after taking a "taste".

After Ultimate Echo Echo defeated Kevin, Cooper finished the machine that would siphon all of the energies that Kevin had absorbed and subsequently cure him with it. Darkstar then betrays the team by using the piece of the Dominus Librium to transfer all said energies into himself, which backfires when Ben; anticipating such a move, activates a switch to return all of the energies back to where they belonged, Kevin then knocks him out with a punch. Kevin, now back to his human form and of sane mind once again, thanks Cooper. He is then given a passionate kiss on the lips by Gwen (much to the disappointment of Cooper) and gets into a argument with Ben about their previous fight, to which he is relieved that everything turned out alright, after which Gwen asks for their help in explaining to her parents about the damage done to their home, to which Kevin and Ben ditch by voting to go to Mr. Smoothies instead, with Kevin buying.

Alternate Future
In the non-canon episode "Ken 10", which takes place during the Ben 10,000 timeline, Kevin was trapped in the Null Void for 32 years. Kevin managed to break out of the Null Void several times. During one of his breakouts, he had his son Devlin with a girl on a Saturn colony.

During his time in the Null Void, Kevin claims to have absorbed the powers of the 11,000 different aliens and monsters trapped with him. This allowed him to turn into a new monstrous hybrid form even powerful than the original one(strong enough to allow him to shrug off multiple direct blows from Way Big), transforming him into "Kevin 11,000". The known powers he can use in this form include his own ability to absorb matter and energy, super strength and durability, pyrokinesis and shape-shifting tentacle, flying wings, slime spit, electric shocks from his left tentacle, sonic howl, and super speed. Having completely mastered his powers, Kevin can now switch between his human and mutant form at will and even access some of his absorbed powers in human form to a limited extent, including super speed, super strength, and durability.

The episode begins with Ben's son Ken celebrating his tenth birthday, and to commemorate the occasion Ben gives him an Omnitrix of his very own. However, he equips it with a limiter, unwilling to trust his son with the power of the Omnitrix or to defeat villains on his own. Ken soon befriends a boy named Devlin, and the same night Kevin 11 attacks (actually Devlin, who has the ability to shift between his human form and his father's first mutant form at will). Unable to locate the Null Void, which Ben had moved after the events of "Ben 10,000", he retreated.

Ken, also unaware of the move, endeavors to find it on his own, only to unwittingly lead Devlin, who is Kevin's son and can transform into his father's mutant form, right to it. Devlin releases his father from the Null Void, but is soon heartbroken to learn that Kevin's only interest is fighting Ben, not seeing his son. Kevin is ultimately defeated by the combined forces of Ben, Ken, and Devlin Levin, to which Devlin, who was kicked out of his family, now hated his father and is later adopted into the Tennyson family after he saves Ben and his son Ken from Kevin's sneak attack. Just before that, Kevin was shown to be at the mercy of Ben, as Way Big, who has lost his temper when Kevin injured Ken and Devlin, and proceeds to viscous beat him. However, Kevin (now in his human form) manages to shrug off the attack with little more than a crick in his neck. Devlin manages to sneak up behind him and traps his father in a Null Void Capsule, which he then gives to Grandpa Max, who, before departing, says "I've got a special place for you this time!", indicating that Kevin will be imprisoned in a special high-security prison instead of the Null Void this time. However, considering how many times he's escaped the Null Void, it is very likely that he will manage to escape from his prison.

Powers and Abilities
Originally, in Ben 10, Kevin's powers were believed to be an unexplained mutation but later explained to be of alien origin. This was proven in "Vendetta", were it is revealed that he is a blood-descendant of the species known as the Osmosians on his father's (Devin Levin) side. Kevin, like all Osmosians, has the unique ability to absorb the energy and matter of anything (excluding certain synthesized materials as seen in "Greetings From Techadon") though his body at will and utilize it in various ways. This includes electricity and any energy within the electromagnetic spectrum as well as the powers, abilities, and memories of other life forms (via absorbing their metabolism, life force, and DNA), fire, water, plasma, and the mass and physical properties of solid matter. Since everything contains either energy or matter, there is no limit to what he can absorb.

Energy Absorption
After absorbing energy, Kevin can activate, overload, and manipulate machinery on physical contact. He can even channel the energy though his hands to discharge it as powerful energy blasts, use it to enhance his strength or use it to increase his cellular regeneration, thus allowing him to recover from injuries at an accelerated rate. However, the energy will dissipate over time or though excessive use, so he is required to recharge.

As said in "Ultimate Aggregor", if an Osmosian were to absorb raw energy, it will risk becoming mentally unstable if all the energy is not discharge quickly, which explains Kevin's violent and sociopath-like behavior as a child. Despite this, there are in fact two known ways to cure Kevin of his insanity. One is to simply let the energy dissipate on its own without absorbing extra energy. The other method is to forcibly drain/siphon of all of the energy Kevin has absorbed, as Ben's team did to Kevin at the end of "Absolute Power: Part 2".

Power Absorption
See: Kevin's mutations

Similar to his ability to absorb energy, by absorbing the DNA, metabolism, and life force of other life forms, Kevin's use it as nourishment to sustain his health and strength. Absorbing the victim's entire energy will ultimately kill the victim. At higher levels he can uses the absorbed energy to acquire the creature's powers and undergoes various degrees of mutation to accommodate the absorbed abilities. Initially, Kevin was able to transform into any of the absorbed aliens' respective forms at will (but could only return to normal for short periods of time). Too much energy at once or an overuse of it (as seen with the Omnitrix and Ultimatrix respectively) will cause the various energies to overwhelm Kevin's body and mutate him further. This new form is a mixed-up and unbalanced version of several if not all the absorbed life forms various aliens; a chimeric or misshapen chaotic amalgamation as Vilgax once said the latter (possibly due to Kevin's underdeveloped powers).

Despite complete access to any of these absorbed abilities at anytime, they aren't as strong as their pure forms, as noticed by Ben who speculated that they only about 1/10 the full power, as seen when Diamondhead was able to catch and crush Kevin 11's crystals with his bare hands while the others shattered upon hitting him. This was explained in Ben 10: Ultimate Alien by Aggregor. He also stated that when Osmosians absorb the life force of other beings, the new powers can only used temporarily unless they were to drain all of that life form's energy, including their life force.

Matter Absorption
While dangerous to absorb raw and life energy, Kevin can safely absorb the properties of solid materials, transmuting himself into a living form of whatever material he has absorbed and subsequently use it to proportionately increase his physical strength and durability. It is revealed in the episode "All That Glitters", that the transmutation serves as a second skin that chips away as he takes damage. In "Plumbers' Helpers", Kevin was able to absorb multiple materials at once. He requires a decent amount of density or mass in the material to completely encase himself (a marble can only produce enough to cover his hand while a Taedenite crystal twice the size of his hand is enough to coat his entire body). This ability has once been used productively when Kevin was forced to synthesize a coating of living Taedenite, thus incapacitating him; Paradox mentioned in Vilgax Attacks" that with the amount Vulkanus chipped off of Kevin is the largest stash in the galaxy.

In season 3 of Alien Force, following Kevin's second mutation caused by the feedback from tampering with the Omnitrix, he loses the ability to revert to his human form but gradually begins learning how to use his absorbed matter in various new manners. He becomes able to use high levels of strength and durability as well as limited regenerative and shape-shifting abilities, seen when he shifts his limbs into a variety of different tools and weapons and restoring his severed hand. Despite returning to normal in "The Final Battle: Part 2" after the Omnitrix self-destructed, Kevin shows in Ultimate Alien to retain his heightened matter manipulation powers due to him now having knowledge of being able to doing so.

In "Too Hot To Handle", Kevin's abilities have shown to develop more, allowing him to repair objects of the current material he has absorbed either by turning it into a liquid or releasing a liquid version of whatever material he has absorbed. He can partially merge with the actual matter and manipulate the substance's form. Both abilities were used when he repaired the rock ceiling of a mine, fused the seal of P'andor's suit, morphed it around P'andor, and fused the arms together as makeshift handcuffs. In "The Creature From Beyond", he used some of the metal he absorbed to create a helmet for Gwen to prevent the Lucubra from controlling her mind. Kevin can easily pick locks, using his powers to absorb the material of the lock, then form his finger into a key. Kevin can also absorb liquids, and when he does he gains the properties of that liquid (e.g. if he absorbs mud, objects will pass through him without causing physical damage).

Other Skills and Abilities
Even without his absorption powers, as an Osmosian, Kevin is shown to be stronger than an average human. While not to the same extent as aliens like Four Arms, Kevin is capable of lifting throwing the combined weight of several people with little strain. He is also capable of resisting impacts and blunt force trauma that would severely injure an ordinary person with moderate discomfort.

Kevin has some noticeable skill in martial arts which he gained during his years as a runaway, a prisoner in Incarcecon, an alien tech dealer, and a member of the Plumbers. With this combat skills, he has proven on several occasions to be a highly formidable fighter, having held his own against and defeated opponents such as the Megacruiser robots, Technorg, and even Vilgax in a one-on-one fight, something that Ben couldn't do.

Despite lacking a proper formal education, Kevin possesses a vast scientific and technological knowledge of alien paraphernalia; he even once mentioned that he learned Astrophysics on the streets. In "Deep", Ben and Kevin argue that they both cannot use their powers while being in their Plumber suits. So Kevin made some alterations to the suits, equipping them with propelling units and shock pulses that allow them to attack with electric shocks. Kevin also has great analytical and deductive skills, having been able to determine specifically what happened in a battle between Aggregor and the Plumbers several hours after the battle, greatly impressing his friends and even gaining a compliment from an experienced Max.

Kevin is a very good driver (both on land or air), being able to race and chase in his car and the Rust Bucket 3. He is also a great at mechanics. He is shown to repair his car for the numerous damage it took during the course of the series. He also modified his car, setting alien tech for beneficial gears. On top of that he built the DX Mark 10, a car that he (reluctantly) gave to Ben as his sixteenth birthday present.

Video Games
Kevin appeared in every version (Wii, DS, PSP, PS2) of the game as the villain at the end of the Lumber Mill level and the second mini-boss in the secret challenge of the Null Void level.
 * Ben 10: Protector of Earth (Villain)

Kevin appeared in every version (Wii, DS, PSP, PS2) of the game, like the previous game. Unlike the previous game, Kevin is playable only on the Wii, PSP and PS2 version of the game. He is playable for levels 2 and 8, and in level 5 he was taken over by a Xenocyte and became the boss for that level.
 * Ben 10: Alien Force (Playable Character And boss)

Kevin appeared once again in every version (Wii, DS, PSP, PS2, Xbox 360) of the game. He is not a playable character in any of the versions.
 * Ben 10 Alien Force: Vilgax Attacks

Kevin appeared as the first boss where he was taken over by the Techadon gauntlet.
 * Ben 10 Alien Force: The Rise of Hex

Kevin is seen in most of the clips in between levels.
 * Ben 10 Ultimate Alien: Cosmic Destruction

Ben 10

 * 4 inch Alien Collection normal Kevin 11
 * 10 cm DNAlien mutant Kevin 11
 * Sumo Slammers mutant Kevin 11

Ben 10: Alien Force

 * 4 inch Alien Collection normal Kevin 11
 * 10 cm DNAlien normal Kevin 11
 * Kevin's battle cruiser (car) - includes metal Kevin 11

Ben 10: Ultimate Alien

 * Ultimate_Kevin_Toy!.png inch Alien Collection normal Kevin 11 (unreleased)
 * 4 inch alien collection Ultimate Kevin (May)
 * Rustbucket III Piece 1 Vehicle

Trivia

 * In Everybody Talks About the Weather, he wears an Olive Green jacket. The jacket reappears in The Perfect Girlfriend.
 * Kevin is the first character to have an episode named after him.
 * When someone asked that if Kevin can grow wings out of his back (in armored form), Dwayne McDuffie confirmed that he can but he can't fly using them, so besides Max, Kevin is only one of the main characters without his own way of flight.
 * Kevin is the only Plumber kid to ever beat Ben in a fight, Pierce not counting because Ben let him win.
 * All the times Kevin was the main character of any episode involves either revenge or has something to do with his mutations.
 * Kevin is the closest character to have as many love interests as Ben (just one short). However, it is revealed in Revenge of the Swarm, that he had some girlfriends before Gwen (he was afraid to tell her), that technically means he has had the most love interests than anybody in the show.
 * For some reason, Kevin shifts between favoring his left and right hand throughout the series, indicating that he could be ambidextrous.
 * Kevin has shown a willingness to kill, most likely attributed to his own harsh life, but he starts to develop not to do this.
 * Following his first mutation from absorbing all the powers of the Omnitrix, Kevin never used, Ghostfreak's or Gray Matter's powers. He never phased through solid objects, telekinesis and didn't become smarter.
 * Kevin has mutated three times in all three series. First from the original Ben 10, then again in Ben 10: Alien Force and most recently in Ben 10: Ultimate Alien. He has only become insane during his first and third mutation though. This is because during the first and third mutations he had absorbed energy, which causes Osmosians to become mentally unstable.
 * Kevin and Gwen find Rath as the most entertaining alien in Ben's arsenal.
 * Dwayne McDuffie confirmed that Ultimate Kevin had every power that Ben unlocked in his Ultimatrix during his third mutation and that "he just never got around to using the hundreds of powers he absorbed".
 * Despite having proficiently good skills in unarmed combat, Kevin is rather ignorant with his array of powers during his first and third mutations, relying only on the abilities that had the most strength (a trait he shares with Ben). It wasn't until he realized the possibilities of his powers that he was able to become more creative in using them to a much greater and dangerous degree.
 * Kevin's car is faster than Ben's as shown in the episode The Transmogrification of Eunice.
 * Kevin loves watching soap operas.
 * Kevin did not go insane after going through his second mutation in because he didn't absorb the feedback of the Omnitrix; rather the Omnitrix rewrote his Osmosian DNA when Ben tampered with it to unlock the Master Control.
 * Kevin and Gwen have kissed three times on screen. Twice in Ben 10: Ultimate Alien and once in Alien Force.
 * Kevin's full name is Kevin Ethan Levin, as shown in War of the Worlds: Part 1.
 * Kevin's original hometown is Bellwood, but he ran away to New York after destroying his family home.
 * Kevin is the first villain in the series to be of Osmosian descent (though he is technically half-Osmosian). The second is Aggregor, who is a full Osmosian.
 * Kevin's very first crime was stealing a bike and used it to run away to New York.
 * The rings Kevin had around his eyes in the original series are a visible sign that an Osmosian has recently absorbed energy, as he no longer had them after he started absorbing solid matter (though he did have them around his eyes after absorbing a shard of energy-charged Taedenite in Kevin's Big Score). This is further evident in Ultimate Alien, as Aggregor (an Osmosian warlord who regularly absorbed energy) had similar rings around his eyes as well and retained them after absorbing the powers of the Andromeda aliens (as he converted their bodies into pure energy to fully absorb their powers).
 * Kevin is the only member of Ben's Team not to have an "evil twin", as Ben has Albedo, and Gwen has Sunny, though he has been compared to Darkstar.
 * It is shown in It's Not Easy Being Gwen that Kevin does not go to high school. Gwen later agrees to help him achieve a GED.
 * In Kevin's second mutation, there was a section of his head covered with some kind of crystal and in a shape similar to some versions of the the mask of The Phantom of the Opera.