In Ben 10: 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 light blue, oil stained, mechanic's jacket over a white muscle shirt, blue jeans, and his black combat boots. After he goes through a 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 time as Ultimate Kevin in Ben 10: Ultimate Alien, his appearance is again an unbalanced mixture of various aliens that were currently accessible to Ben through his Ultimatrix.
Appearance in UltimaEdit
Kevin fights for the Society with his special absorbing powers. He often teams up with Ben and Gwen Tennyson while on missions and can be incredibly powerful. Kevin has fought powerful enemies including Vilgax, Vlad Plasmius, and even his own past self. The Organization has also used Kevin's appearance to create duplicates of him as part of the AntiHero project.
He sometime worry that his old self will haunt again, even if it's a clone or an unknown being. he still in relationship with Gwen who still care and comfort for he's going through, even in a fight