Kevin Levin (Classic)

Kevin Ethan Levin (voiced by Michael Reisz in his first appearance, Charlie Schlatter in his following ones, and by Greg Cipes in Ben 10: Alien Force) is a human-alien hybrid with the ability to absorb any type of energy and release it at will, though he seems only able to release electricity, or he may simply favour this due to it's offensive potential. The energy can be used to activate or overload various machines and can also be used to make energy blasts.

Ben 10
Kevin was abandoned before the start of the series due to his powers, and has been alienated ever since, this has lead to him developing anti-social behavior disorders that border on sociopathy, however, he is reformed over the course of Ben 10 Alien Force, and rejoins society and apparently recociles with his family. When absorbing energy from the Omnitrix's aliens, he becomes an incomplete, but effective, version of that alien. In his first appearance in "Kevin 11", he is first encountered by Ben Tennyson in an arcade, where he was assaulted by bullies and saved by Ben as XLR8. The two attempt to steal video games from a warehouse and get caught by the police, forcing Ben to reveal his powers to him in order to escape. Eventually, Ben breaks off their partnership when Kevin rigs two trains (one carrying money) to collide in, not caring that hundreds of innocent people would be killed. He then absorbed the abilities of Heatblast and Fourarms, using the former form's powers to get revenge on those who had wronged him. He absorbed the latter form's powers during his second battle with Ben to even the odds. After trying to take the Omnitrix from Ben, the Omnitrix emitted a feedback pulse to prevent Kevin from taking it, seemingly neutralizing his power. Kevin, however, exhibits the ability to create flame at the end of the episode.

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 crime spree in Los Angeles, 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 would describe as a "misshapen, chaotic amalgam of creatures from the Omnitrix." This form has: Fourarm's head, body, left eyes and legs, Grey Matter's right eye, Upgrade's upper back, Stinkfly's wings, Diamondhead's right arm, Heatblast's left arm, Wildmutt's arms below them, Ghostfreak's lines, XLR8's tail, and Ripjaw''s antenna, gills, and teeth. ''

After his mutation, Kevin gloats that he has all of Ben's powers plus his own, making him "Kevin 11" (the name Kevin is credited under in the ending sequence of the show). He has Stinkfly's ability to fly and his slime spitting. Diamond Head's diamond ability with his right arm. Fourarm's strength. Wildmutt's sniffing ability. XLR8's speed. Heatblast's ability to shoot fire out of his left arm. Ripjaw's bitting (possibly also his ability to breath under water because he has Ripjaw's gills). Although Kevin does not have all of the powers of the omnitrix aliens he copied. He does not have Grey Matters intelligence, Upgrade's ability to take control machines and his lazer vision, and Ghostfreak's ability to turn invisible and his ability to walk through walls. Despite Kevin's claim, Ben notes that Kevin's powers are only one-tenth as strong, (although this assessment may not be accurate) and Kevin never exhibits his original powers in this form (the same is true for Ghostfreak, Upgrade (though this is debatable when Kevin used XLR8's tail to slam a tray of Megacruiser food into Technorg's face), Grey Matter, or Wildmutt. Kevin's form also limits his ability to use the special powers of his alien forms. Being a random fusion of aliens, Kevin only has access to the powers most prevalent in his form. In addition to these limitations, Kevin seems unable to use the powers of any aliens Ben has gained since their original encounter.

During his third appearance in "Grudge Match", Kevin attacks Ben to get revenge, blaming his condition on Ben. As the two battle, they are abducted and forced to fight in Slix Vigma's gladiator games. During their battles, Ben helps Kevin to realize the advantages of his mutated form. Because Kevin 11 is an amalgam of aliens, he can mix and match their powers to make up for their reduced potency. Although forced to work together, Kevin's only goal was killing Ben. He is transported to a different galaxy at the end of the episode while locked in combat with Technorg, who beat him then escaped. He then took the ship as his own.

Kevin returns in the episode "Back With a Vengeance", where he teams up with Vilgax to defeat Ben, and eventually manages to remove the Omnitrix. However, he betrays Vilgax later in an attempt to leave both 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.

Ben 10: Alien Force
Kevin returns in Ben 10: Alien Force as an ally of Ben and Gwen Tennyson. Kevin's powers operate differently from the way they did in the original series. He has a normal human form, seemingly lost the powers of Ben's Omnitrix aliens, and his absorbing abilities now allow him to absorb the properties of matter as opposed to draining energy, allowing Kevin to cover himself and others with a layer of any solid substance he is touching (similar to Marvel's Absorbing Man) which also grants him some level of superhuman strength (Dwayne McDuffie has mentioned that Kevin can still absorb energy, but "He's afraid to". This may be because of what happened when he absorbed Ben's Omnitrix Aliens). He has a green hi-tech sports car which he takes care of obsessively. In his spare time, he installed various alien technologies in the vehicle, which proved useful in the final Highbreed war where he was forced to sacrifice it. Through the years, Kevin has gained a considerable amount of knowledge about aliens, possibly through his brokering of alien technology to various aliens and the Forever Knights and probably due to the fact that he is the son of a Plumber as well. He also seems to know a lot about humans with an alien heritage, as his guess about Gwen's powers being of alien origin was proven correct. As revealed in the episode "The Gauntlet", Kevin, as mentioned by JT, is now reputed as "the toughest kid in town", indicating that he has taken up residence in Bellwood although this has never been explicitly stated, nor is it mentioned how he could've escaped the Null Void or how he returned from his mutant form, however, it is possible that as his powers matured, he gained the ability to return to his human form. It is worth noting that when Ben first defeated Kevin, he offered Kevin to join their group; a similar thing happened at the begining of Alien Force, when Ben defeated Kevin as Swampfire and he was once again offered to join them, this time he took it.

In "Darkstar Rising", he reveals that his father was also a Plumber. He never met his father, but 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 electrical powers but it may have only been an exaggeration on his part, since it is slightly hinted that Kevin's mother remarried, due to him saying, "My father, my real father". It's is also possible that he had somehow ended up it foster care, and that it was these parents that left him. At the end of the same episode, Kevin, along with Gwen and Ben become official Plumbers, after which, Kevin leaves to tell his mother about his membership, this suggests that he has now reconciled and rejoined with his family. 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.

In the season 3 premeire "Vengence of Vilgax", Kevin is subjected to feedback from the Omnitrix after Ben tampers with it. Because of this, he is unable to revert back to his normal human form.In Alien Force Kevin drives around in a green muscle car that he modified with alien technology. It was once destroyed during the sries by a time aging monster, but Paradox brought a new car thats the exacts sam model from the past.In Alien Swarm the Live-Action movie Kevin is seen driving around with his car. The car is a green 2009 Dodge Challenger.

Kevin's Abilities
Kevin's abilities have somewhat changed through out the course of the series. Generally, his power revolves around absorption. In Ben 10, Kevin can absorb energy and manipulate machinery to a minor extent though the energy he uses is finite, so is required to steal more. By absorbing energy from the Omnitrix, Kevin can temporarily take on attributes of any alien form Ben has currently taken on.

In Framed, it is revealed that Kevin is able to assume any of Ben's alien hero forms at will, due to having absorbed enough sufficient energy from the Omnitrix. Despite this advantage over Ben, he is still defeated. The rage causes his absorption power to spiral out of control, mutating him into a hulking behemoth fusion compromised of the ten starter Omnitrix aliens with no way to revert back to human form. He remains in this form for the remainder of Ben 10. According to the enhanced version of "Framed" Kevin's human DNA restores through time. So, after 5 years he will become a human again.

In Ben 10: Alien Force (5 years after the Ben 10 series), Kevin returns in human form with his absorption powers intact. However now, he is able to absorb the properties of material into his own being such as metal or rock, transmuting himself a living form of whatever material he has absorbed and use it to increase his physical strength. It is revealed in the episode All That Glitters that the transmutation actually serves as a second skin/coating that eventually peels away as he takes damage. In the episode Plumbers' Helpers, Kevin can absorb multiple materials at once, as demonstrated by absorbing both nickel and bronze (from a penny). A Popup stated that Kevin can, in fact, still absorb energy, but he is "Afraid to", a plausible reason, considering his previous mutation. He requires a decent amount of material to completely encase himself. This abiltiy has once been used productively when Kevin was forced to synthise a coating of precious material, with the coating thickening after multiple absorbions to the point where Kevin couldn't move.

In the Alien Force season 3 premiere, Kevin loses the ability to revert to his human form after a feedback blast, caused when Ben tampers with the Omnitrix, imprints various materials onto him, such as concrete, metal, wood,;what appears to be Diamondhead crystals. in addition, Kevin gains limited shapeshifting abilites, seen when he shifts his hands into a variety different tools, such as a mace and large clippers. It is unknown if this is a permanent conditions, or simply temporary.

Possible future
In "Ken 10", Kevin returns after at least thirty years of imprisonment in the Null Void (though he has been sent in and out several times prior to the episode), having been set free by his son, Devlin Levin. Devlin was born after one of these escapes in which Kevin fled to a colony on Saturn, where he started a family before being captured again. Kevin has now fully mastered his powers and can return to his human form. In his human form, he can also utilize the powers he has absorbed to a limited extent, such as XLR8's speed, without having to transform into that alien, and is able to simply shrug off an intense beating from Way Big. His mutated form, though still an amalgam, has changed considerably from his continued absorption of alien DNA, leading to his new title of "Kevin 11,000". Eager for revenge and having not so much as a care for his son, despite Devlin's role in releasing him, Kevin proceeds to beat on Ben and his son, Ken. Ironically, it is Devlin who stops him, trapping his father back in the Null Void. Besides still having Wildmutt's arms, Stinkfly's wings, and Fourarms' legs, he now has:


 * A Heatblast-like head, body, left wing and right tentacle, but black instead of red.
 * A left tentacle that splits in the middle into a Fourarms' arm and a tentacle with Upgrade and XLR8 tail markings
 * Several grey tentacles (similar to the tentacles of the Null Guardians featured in "Truth" and "Back With a Vengeance") protrude from his lower body.
 * Sonic howls similar to that of Benwolf
 * Wildmutt's arms
 * Stinkfly right wing
 * Fourarms' legs

Trivia

 * According to the Pop-up version of the original Ben 10 series episode, "Perfect Day", it is revealed that Gwen Tennyson had feelings of sympathy for Kevin. This then grows into love in Ben 10: Alien Force.
 * In the Ben 10: Alien Force season 2 finale War of the Worlds, Part 1, it is revealed that Kevin's middle name is Ethan, making his full name Kevin E. Levin, officially connecting the pun to his old nickname "Kevin Eleven". Ben finds this extremely hilarious, saying that he has lost "all remaining pretense of 'cool".
 * He may be part alien because he said that his dad was a plumber. Even though his parents supposedly abandoned him (this may be a lie Kevin invented to impress Ben, because he doesn't answer to anybody), Kevin still has a mom who has most likely remarried, because on the end of Darkstar Rising, Kevin tells Ben and Gwen that he will tell his mom about his new plumbers badge.
 * Gwen hardly said two words to Kevin in Ben 10, but they interact in almost every Alien Force episode. Throughout the Alien Force series, Kevin has developed romantic feelings for Gwen, which has more than once been evidenced, although he is very reluctant to openly admit them which could be due to the fact that he is very self-conscious and concerned that it will never work out between them for obvious (if not too obvious) reasons, his checkered past, his lifestyle, as well as just being the pretty much opposite of her. However, in "War of the Worlds", Kevin demonstrates just how much he really cares about Gwen after she transformed into her Anodite form, by reaching out to her by saying that he doesn't want her to forget him or Ben and that he doesn't want to lose her, they embrace each other afterwards. At the end of the show Kevin also takes Gwen to the auto show.
 * Although seldom emphasized in the series, Kevin has a slight similarity to Max Tennyson, having first been pointed out by Verdona in the episode "What Are Little Girls Made Of?", this is supported by their similar personality traits, stubborn, adventurous and straightforward. Kevin has also worn Max's old tuxedo in "Save the Last Dance", possesses extensive knowledge about aliens rivaling that of the latter, as well as having a potential romance with Gwen, who is also of the Anodite heritage, reflecting Max and Verdona's past relationship.
 * Kevin's mutated form in the season 3 debut bears a striking resemblance to DC Comics Metamorpho and even possesses similar powers.
 * Kevin has been unable to transform back to his human form twice now. Both times were from tampering with the Omnitrix.
 * Kevin is Dyslexic