Kevin was a thin and scrawny boy with shoulder-length black hair, pale skin and dark brown eyes with black-discolored marks around them (a sign that an Osmosian has recently absorbed energy). He wore a torn black t-shirt, black studded arm bands, brown cargo shorts, gray knee-length boots, and a padlock necklace which was a spoil from his first crime: stealing a bike and using it to run away to New York. After absorbing an Omnitrix feedback, Kevin becomes able to transform into exact copies of all of the unlocked aliens, missing an Omnitrix symbol. When Kevin was 11, he was a criminally insane sociopath, willing to hurt/kill anyone for his own personal gain and/or pleasure. This behavior and mentality stems not only from being seen and treated as a freak by his peers and family, but also because of the side effect of Kevin absorbing energy. His selfishness and sociopath-nature is made apparent when he was once willing to derail a money train to steal the money and kill countless passengers on another train. Kevin had an extremely negative outlook on life because of the countless hardships and struggles he had, feeling insecure about himself as well as having incredibly low self-esteem. He had a deep-rooted hatred for other people and society in general, even the innocent as he once said "Nobody's innocent! They just haven't had the chance to make fun of me yet!". Kevin and Ben no longer share their famous rivalry and instead have become true friends. Kevin acts as an older brother towards Ben. They care genuinely for each other. Kevin is much more open about his feelings, showing gratitude and tries to express it to both Ben and Gwen (mostly Gwen). Gwen and Kevin continue their romantic relationship. He also seemed to have a better connection towards Max. During his time in the Null Void, Kevin claims to have absorbed the powers of 11,000 aliens. This allowed him to turn into a new mutation, called Kevin 11,000, more powerful than the Kevin 11 (durable enough to allow him to shrug off multiple direct blows from Way Big). The known powers Kevin 11,000 has include his ability to absorb matter and energy, super strength and durability, pyrokinesis, shape-shifting tentacle, flight, slime spit, electric blasts from his left tentacle, sonic howl, and super speed. Having mastered his powers, Kevin can now switch between his normal and Kevin 11,000 at will and access some of his absorbed powers in human form to a limited extent, including super speed.