Zapp Renfro

Described as a hotheaded, hyper-sexual juvenile punk, he is easily annoyed, quick to lose his temper, and his juvenile actions often get him and others into trouble.

Despite this, he is supposedly good at looking after new members, and so was assigned as Leo's partner/bodyguard. He is also something of a ladies man, possessing several lovers in town.

For reasons unknown, he continuously tries to fight Klaus, only to be routinely smacked down.

(Source: Kekkai Sensen Wiki)