Кайман

Kaiman usually takes on the personality of someone arrogant and lazy, but deep inside he's rather caring and cares a lot for his best friend, Nikaido. Rude, stubborn and prone to resolve anything with violence, there's a few things in Kaiman's mind and heart, wishing to have his normal head back, eat gyoza and having more money (in that specific order); only caring about subjects related to those three things and showing no regard or concern about anything else. He sees Magic Users as scum, killing them in the spot after interrogating them and showing no remorse for that, he hates them and he even would start a mass slaughter in the middle of their realm to find the one responsible for his head.

He has constant nightmares about his creation and death, causing Kaiman to wake up tired, worried, scared and trying to forget them, even if sometimes they have a connection to his past. He has shown to be easily distractible as during both his jobs he finds himself easly distracted by things.

Kaiman does eventually get his human face back, along with his lost memories, but the truth about his identity was more than he bargained for. It turns out he was originally a human boy from Hole named Ai Coleman. Ai put himself through surgeries to become an artificial magic user, and his self has since fragmented into several quasi-independent personalities attached to multiple heads, including Aikawa and Kai. Kaiman actually wore one of Kai's heads for most of his time in Hole, as indicated by the crosses he had around his eyes. He switched to Aikawa's crossless head when he experienced a flashback at the Zagan school of magic.

Kaiman was still wearing Aikawa's head during his fight with En when Ebisu's reptilian magic was dispelled, which is why he reverted to the Aikawa personality and not Kai at that time.