Kevin's Mutations

Kevin's mutations are caused by his Osmosian ability to absorb, hold, redirect, and discharge virtually any type of energy or matter through his body. By absorbing energy from Ben's aliens or from the Omnitrix/Ultimatrix itself, the energy and DNA will cause him to mutate into a conglomeration of all of Ben's aliens.

Original series
In the original series, Kevin simply absorbed electricity or the DNA from Ben's current alien form, turning him into an incomplete but powerful and effective version of that alien, earning the abilities of the alien he had absorbed. Shortly after trying to get revenge on a gang of bullies that had tormented him, he was exposed to a massive energy feedback that he inadvertently absorbed. The energy was sufficient enough so that Kevin could shape-shift between any of the 10 original aliens in the Omnitrix. However, his ability to regulate the power was weaker than that of the Omnitrix, forcing him to stay in an alien form most of the time. Later, during a fight with Ben on the Golden Gate Bridge, Ben put Kevin into submission and, at first, looked like he was going to kill him. Instead, he deliberately missed walked away, stating that Kevin was never worth it. Kevin however, wanted to continue fighting became enraged. His rage, combined with all of the energy and DNA he absorbed, caused his absorption powers to spiral out of control, causing him to mutate him into a hulking chimerical behemoth fusion of the 10 original starter aliens of the Omnitrix, which Kevin dubbed the form Kevin 11 (due to having all of the powers of the 10 starter aliens from the Omnitrix and his own powers). Kevin was powerful in this form, but only had, or showed, the abilities of the aliens most obvious in his of all ten of Ben's aliens. Being, as Vilgax put it, a "misshapen chaotic amalgam of creatures... from the Omnitrix", his powers weren't as strong as Ben's pure versions and only had about one-tenth of their original strength. However, he is capable of mixing the abilities to his advantage, such as using Heatblast's flames and Stinkfly's goo to form an explosive attack, or using XLR8's speed, Fourarms' strength, and Diamondhead's invulnerability for, as he put it, "one mean punch". Kevin also proved strong enough to hold his own against the Megacruiser robots, technorg, and Vilgax in a one-on-one fight, something Ben has never acomplished.

After approximately 5 years in the Null Void, his human DNA overwrote the alien DNA, causing Kevin to lose this form in the Alien Force timeline. However, in the Ben 10,000 timeline he kept absorbing alien DNA, becoming Kevin 11,000, who is non-canon.

In the Ben 10,000 timeline, Kevin has a son, Devlin Levin who could could transform into his father's original chimerical mutant form, though Devlin did not appear to have the same power set-back as his father.

In the Ultimate Alien episode, ...Nor Iron Bars a Cage, it is revealed how Kevin changed back to normal from this mutation. When he becomes a prisoner after being trapped in the Null Void, he was met by another prisoner named Kwarrel, who Kevin soon came to help for. Kwarrel taught Kevin how to control his anger and powers. Soon enough, Kevin becomes sane again, and returns to his human form.

Appearance:
 * Kevin's hair, ears, and cargo shorts
 * Four Arms' frame, arm count, left eyes, legs, head, and torso
 * Heatblast's upper left arm
 * Stinkfly's wings
 * Upgrade's upper back
 * Diamondhead's upper right arm
 * Ghostfreak's track
 * Grey Matter's right eye
 * Wildmutt's lower arms and gills/nose on his face
 * Ripjaws' lure (Four Arms' skin), teeth, and gills on his torso
 * XLR8's tail

Abilities:
 * Kevin: Matter and energy absorption
 * Four Arms: Super strength
 * Heatblast: Fire blasts
 * Stinkfly: Flight and slime spit
 * Upgrade: Plasma beam (Never shown)
 * Diamondhead: Shapeshifting arm, crystal shards, and invulnerability
 * Ghostfreak: Invisibility and intangibility (Never shown)
 * Grey Matter: Superhuman intelligence (Never shown)
 * Wildmutt: Superhuman agility, senses (via gills/nose on his face), and quills
 * Ripjaws: Glowing lure, underwater breathing, and steel-bending jaws
 * XLR8: Super speed

Alien Force
In Vengeance of Vilgax, while Ben was trying to hack the Omnitrix, the Omnitrix overloaded. Kevin tried to help Ben by trying to override the system, but instead he got blasted by the feedback that the Omnitrix created. He turned into a mutation of every solid material he had ever absorbed (steel, concrete, stone, and taedenite). During his time in this form, Kevin learned that he can shapeshift his limbs into various tools and weapons and had limited regenerative abilities. In addition, his superhuman strength and durability was further increased.

In Trade-Off, Kevin teamed up with Darkstar to turn back to normal. He succeeds but lost his powers, making him least useful to the team. Gwen finds out what he did and goes after Darkstar. Darkstar then absorbs all of her power, and Kevin realizes the only way to save her is to stop Darkstar. After the fight with Darkstar, he got his ugly mutation back (so did Darkstar), and Gwen was saved.

In Time Heals, Gwen tried to turn him back to normal by going back in time and stopping the disaster, but later learned that it had to happen after Charmcaster made Kevin a rock slave.

He turned back to normal in The Final Battle: Part 2 when the Omnitrix is destroyed in battle. According to Max, the Omnitrix kept him in that form.

Appearance:
 * Kevin's briefs
 * Taedenite: Half of face
 * Stone: Half of chest, half of face and left arm
 * Metal: Half of chest and right arm
 * Wood: Legs

Abilities:
 * Kevin: Turning hands into weapons

Ultimate Alien
In The Forge of Creation, in order to stop Aggregor from absorbing the powers of a newborn Celestialsapien, Kevin had no choice but to absorb the Ultimatrix's powers and turn into, as Vilgax would call it, a a misshapen chaotic amalgam form of the creatures of the Omnitrix except it is from the Ultimatrix. This form, dubbed Ultimate Kevin, is very powerful and very quickly and easily defeated Ultimate Aggregor before draining him of his powers. However, Kevin's personality has become even worse than it was in the original series. This form doesn't seem to have the same set-back as the first mutation ( his powers only being 10% of their original potency), though whether or not this is true is unknown.

Throughout ...Nor Iron Bars a Cage, The Enemy of My Enemy, and Absolute Power, Ultimate Kevin goes rampant on attacking people who either owed him or he wanted revenge on. Fortunately, Kevin still seems to have some control his sanity, as he willing spared an opposing Gwen. Either way, Kevin is too powerful for anyone and Ben thinks "putting him down" is the best option.

In Absolute Power, Kevin's self-control is almost entirely overtaken by his insanity. He has now developed an insatiable hunger for energy and begins to drain the life force and powers of other beings. Ben still thinks that eliminating Kevin once and for all would be the best choice. Gwen, however, sees that the power is controlling Kevin's mind. Gwen deliberately tries to help Kevin by talking. He reveals that he still had a single shred of humanity that allowed him to deliberately stay away from Gwen, knowing that his remaining willpower would be overwhelmed by his insanity and that he would end up draining her dry if he got the chance. Against all odds, Gwen still tries to reason with him. Kevin's willpower is then overwhelmed by his hunger and he ends up partially draining her of her life force and powers, nearly killing her in the process. He then becomes obsessed with her overwhelming amount of energy and ends up tracking her over the rest of both episodes (though his feelings for her prior to his mutation become mixed with his insanity, as seen when he commenting that he thinks she's deliberately avoiding him and how he shows jealousy when Cooper tries to stop him from killing her and nearly kills him as well). Gwen later teams up with Darkstar to defeat Ultimate Kevin by stripping his powers using a Dominus Librium fragment.

Ultimate Kevin was cured in Absolute Power: Part 2. However, Darkstar becomes Morningstar (Ultimate Darkstar) again by absorbing the powers from the Dominus Librium which had absorbed Kevin's powers. Fortunately, Ben anticipated this from the beginning and presses a button which not only strips Morningstar's new powers, but returns the abilities to their rightful owners as well as reviving the five Andromeda Aliens.

Appearance:
 * Kevin's hair
 * Four Arms' frame, arm count, and torso
 * Jetray's right foot, three-fourths of his face, back, right eyebrow, eyes, and mouth
 * Diamondhead's right arm structure
 * Spidermonkey's lower right arm
 * A hooded blue cape modeled after Big Chill's cloak that can shape-shift into a pair of wings and antennae
 * Swampfire's left arm structure
 * Lodestar's left shoulder spike and right claw (Diamondhead's arm structure)
 * Humungousaur's chest plates and tail
 * One-fourth of Ultimate Humungousaur's face
 * Two of Chromastone's crystals on his right shoulder in place of Lodestar's right shoulder spike
 * Two of Brainstorm's legs in place of a lower left arm
 * Goop's right arm (can turn into Lodestar's right claw)
 * Rath's left arm (Swampfire's arm structure), left wrist claw, and left foot (Jetray's skin)
 * Water Hazard's water ports on his hands
 * Ultimate Spidermonkey's split lower jaw( Jetray's skin)

Used Abilities:
 * Kevin/Aggregor: Energy and matter absorption
 * Swampfire: Fire blasts, seeds, and chlorokinesis
 * Humungousaur/Ultimate Humungosaur: Super strength and durability
 * Big Chill: Ice breath, flight, and intangibility
 * Chromastone: Ultraviolet blasts, Energy absorption
 * Brainstorm: Electric blasts, force fields, and telekinesis
 * Jetray: Nueroshock blasts
 * Goop: Liquefaction and stretching
 * Rath: Wrist claw and aggression
 * Diamondhead: Shapeshifting arm and crystal shards
 * Water Hazard/Bivalvan: Water blasts and invulnerability
 * Armordrillo/Andreas: Jackhammer arm
 * Terraspin/Galapagus: Aerokinesis
 * NRG/P'andor: Heat generation and radioactive beams
 * AmpFibian/Ra'ad: Levitation
 * Echo Echo: Sonic scream
 * Ultimate Spidermonkey: Web spit
 * Lodestar: Magnetism manipulation
 * Alan Albright/Heatblast: Pyrokinesis
 * Gwen/Rock Monsters: Mana blasts
 * Helen/XLR8: Super speed
 * Manny/Fourarms: Super strength
 * Dr. Vicktor/Benvicktor: Lightning redirection
 * Pierce: Spike generation
 * Map of Infinity

Possible future
In the episode Ken 10, which takes place in one of the possible futures, Kevin escapes the Null Void with the help of his son Devlin and declares that during his time there, he absorbed the power of all other aliens trapped with him, becoming Kevin 11,000.

Appearance:


 * Heatblast's torso, right tentacle, head flame, and right shoulder flame,left wing in the shape of Stinkfly's.
 * Four Arms' body frame, feet and left arm
 * Ghostfreak's head shape, right eye, and body track
 * Wildmutt's lower arms
 * Upgrade-patterned tentacle jutting out of the left forearm, tipped with the pattern from XLR8's tail
 * A Null Void Guardian's tentacles protruding from his backside like a tail
 * Stinkfly's wings (Heatblast's structure for left wing and Diamondhead's structure for right wing)

Known Abilities:
 * Kevin: Can shift from Kevin to Kevin 11,000 at will, energy and matter absorption, retains certain powers he absorbed in his human form to a limited extent
 * Stinkfly's flight and toxic saliva
 * Can shapeshift his right tentacle in a similar fashion to Diamondhead
 * Can release electricity from his left tentacle similar to Buzzshock
 * Benwolf's sonic howl
 * Four Arms super strength
 * XLR8's super speed
 * Wildmutt's superhuman senses, agility, and quills

Pyronite DNA


Kevin is mutated in this form after absorbing some Pyronite's DNA from Ben in the form of Heatblast, when Kevin wanted to crash two trains, one filled with passengers and the other filled with money that he wanted to steal, so Ben attempts to stop him as Heatblast but Kevin sneak behind him and absorbs Heatblast's DNA.

Kevin looked like an incomplete version of Heatblast, having a different face, one of his arms mutated and part of his chest while displaying Heatblast's pyrokinetic abilities.

Tetramand DNA


Kevin is caused by this mutation with DNA Tetramand when Kevin goes with his new powers. As the form of Heatblast, Kevin goes to the bridge where the gang lived bothered him while Ben and the others travel there to prevent this from doing something stupid, Ben comes before and Four Arms while Kevin absorbs Four Arms DNA. The mutation left Kevin with Fourarms left eyes, his right human eye, his hair, black nails on his upper arms, and four additional human arms.

Rock Monster
It is not known exactly when Kevin takes this form, this happens in the Time Heals, it is believed that Kevin was somehow pressed to absorb one of the Rock Monsters used by Charmcaster, thus giving Charmcaster and Hex total control over Kevin, making him their slave and unwillingly fight Gwen and Ben as Spidermonkey

After ignoring Professor Paradox's warnings about Time-traveling, Gwen changes the future by preventing the hacking of the Omnitrix and the mutation of Kevin, but after succeeding and returning to her timeline, she sees what could happen in the future if the accident had never occurred, making Gwen rearrange everything again back to the way it was.

Kevin changed his appearance to having rock skin, purple eyes and having Charmcaster's Rock Monsters lines and markings imprinted over his body.

DNAlien Kevin
In Ben 10 Alien Force the game Gorvan atached a Xenocite to Kevin forming DNAlien Kevin. He retains Kevins matter and energy absorbing powers and also posesses the enhanced strenght and slime spit of a DNAlien.

Trivia

 * Kevin's mutations are an Osmosian trait (which he inherited from his father Devin Levin) as the full Osmosian villain Aggregor is shown to be capable of absorbing & assimilating alien DNA which allows him to gain their abilities and causes a slight mutation (though nowhere as extreme as Kevin's). Kevin's mutations are a result of this ability, though he is unable to control his mutations and has trouble keeping a stable mental state due to inexperience (as Kevin 11,000 is able to keep a stable mental state and has shown the ability to retain certain alien abilities he has absorb while in human form, such as XLR8's super speed).
 * Kevin's alien mutations all have the frame of Fourarms (red, bulky, and two sets of arms).
 * During his third mutation, Kevin's wings seemed to have shape-shifting abilities as whenever the hood unfolded it seemed to be thinner than when folded up and the wings seemed to lose and gain certain aspects/parts when unfolding and would "fuse" together to form the cape when folded up.
 * Each of Kevin's canon mutations have a unique trait to them before/after being cured:
 * 1) After being cured from his first mutation, his clothes are completely intact even though the initial transformation completely destroyed his clothes (except his cargo shorts).
 * 2) His second mutation destroys his clothes completely (except his briefs). This isn't undone upon being cured like the first mutation His second mutation is the only one in which he retains his original body frame and does not lose his sanity.
 * 3) His third mutation, unlike the first, doesn't restore his clothes, with only his pants intact.
 * 4) When the kids hacked the Omnitrix and damaged it, it sent out a wave of energy that rewrote Kevin's Osmosian DNA, only possible because of Osmosians absorption powers. Confirmed by Dwayne McDuffie.