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Ultimate Kevin Levin is the mutation Kevin Levin went through in Ben 10: Ultimate Alien.
Ultimate Kevin was composed of a larger pool of aliens than his earlier mutations, with multiple parts of his body now being combinations of multiple aliens. His face mostly resembled Jetray's but had Kevin's hair, a patch on his left eye consisting of green skin and Humungousaur's eyebrow, and a jaw belonging to Humungousaur that split like Ultimate Spidermonkey. His torso came from Humungousaur but had a backside colored like Jetray. Draped over it was the cloak/set of wings of Big Chill but without the patterns. His right arm was crystalline like Diamondhead and his first mutation, but also had two magenta crystals on his shoulder resembling Chromastone's, and his hand was shaped like one of Lodestar/Brainstorm's pincers. His left arm mostly resembled Swampfire 's, but with a shoulder spike belonging to Lodestar and a hand and wrist claw belonging to Rath. His right foot resembled Jetray's, while his left foot resembled Rath's. He also had Humungousaur's tail, two of Brainstorm's legs in place of a secondary left arm, one of Spidermonkey's arms as a secondary right arm, and Waterhazard's portholes on both his Swampfire-like hand and Lodestar/Brainstorm-like pincer.
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