Amaury St. John, the friendly hoodoo man of team black. A lovely man who can be friends with just about anyone, regardless of how good or bad they are, and will always make sure that a kindness is repaid in full, just don't do anything nasty to him, because no matter how much he likes you he will do something equally nasty back. It's nothing personal, but fair is fair after all.

Strictly speaking, Amaury isn't fighting for the Yggdlmillenia cause per say. Rather, he joined the family because doing so constituted a rejection of the Mage's Association, an act he feels is sufficient enough to constitute adequate revenge. It is also possible that someone on the Black team did him a kindness that he is currently attempting to repay, but such things can be hashed out later.

Friends: Just about anyone Amaury meets can be considered a friend to him. Yes, even people on the Red team. Just because he has to kill them doesn't mean he can't be friendly.
Enemies: Strictly speaking it is nearly impossible to make Amaury consider someone an enemy. However, regardless of his level of affection for someone, if he is wronged he will wrong them right back.
Lovers: He's had a fling or two, but nothing serious.
Others: I'd love for Amaury to get the most evil, monstrous, and/or outcast Servant he can, just to highlight how accepting of others he is. Whether a true friendship forms or this ends up biting him in the rear Scorpion and the Frog style can be decided later.