Yeah, I know it's sappy. And yes, it's yaoi.
Fox is actually named Arqubis du Tarsier, and is a noble, but he doesn't tell anyone this until near the end of the story. (Although it is foreshadowed once). He gets his nickname from Ledon the Bard, who decides that he is The Fox of the Shir, Hero Extrodinaire. Much to Fox's annoyance, the name Fox catches on, and soon many people are calling him THE Fox.
Fox is a mage, like Leona. Unlike Leona, he uses his magic in an almost subconscious way. It allows him to fight even when he shouldn't be physically able to, and he heals much faster than a human should. He's a little bit faster and hits a little bit stronger than you think he's possible of doing, and can jump like a panther. It also allows him to talk to canine species, such as wolves. He can use magic to sense his surroundings, and sometimes can feel other peoples' emotions, though his is not aware that he can.
Reanna takes a liking to Fox almost immediately, and eventually falls in love with him. To bad it's not mutual.
Fox has had many roles in his life. He was a thief for a while, and so is highly skilled at sneaking, being extra quiet, and picking locks. He favors doing things a bit different from what Michael wants to do. Michael wants a just and fair war, with no tricks. Fox wants to assasinate Chanton. They get into a few arguments about this.