Zero

A lone wolf who has been banished by other wolves because he is an OPT. He taught Jio all he could of fighting and survival skills. He hates both humans and wolves, but built up a friendship with Jio as they share similar situations - they are both shunned by others of their species. His bones are C Rank O-Parts, and their Effect is Haste, but using them causes extreme pain to Zero. In post time-skip, he travels with Jio.