Kevin 11 (character)
From Wikitrix
By all outward appearances a rebellious teenager, Kevin is actually a sociopath that Ben meets after having an argument with Max. Kevin has the unique ability to absorb any type of energy and release it at will. The energy can be used to activate or overload various machines and can also be used to make energy blasts. 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 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. As a side effect, however, Kevin's ability to regulate this power is poorer than that of the Omnitrix itself, causing the energy to suppress his human form and forcing him to remain as an alien most of the time. As revealed in "Framed", Kevin blamed Ben for this, so he uses the powers of the Omnitrix to commit crimes, 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 altogeter, causing him to permanently mutate into what Vilgax would describe as a "misshapen, chaotic amalgam of creatures from the Omnitrix"[2]
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). Despite Kevin's claim, Ben notes that Kevin's powers aren't as good as his pure version (he quips that they're only one-tenth as strong, though this is likely not an accurate assessment), and Kevin never exhibits his original powers in this form. Kevin's mutated 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 gladiator games. During their battles, Ben helps Kevin to realize the advantages of his mutated form. Because Kevin 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.
Kevin returned in the episode "Back With a Vengeance", he teams up with Vilgax to defeat Ben,and eventually manages to remove the omnitrix.But he betrayed Vilgax later in an attempt to leave both in the Null Void, only for Ben to escape and leave him and Vilgax trapped.
While it is confirmed in "Ben 10,000" that Vilgax eventually escapes, it is unknown if Kevin ever does.
He appears in "Perfect Day" as a vision in Enoch's dream machine but his "Ripjaws" mouth is showing.
Kevin 11 makes an appearance in "Ken 10" as an adult released from the Null Void Dimension with help from his son Devlin later is defeated by his son Devlin and the Tennyson Family.
