I guess the closest thing Assassin's Creed Revelations gets to bosses are those special assassination targets, so my boss would be Tarek, leader of the Ottoman janissaries, who, it turns out, kinda didn't deserve it, which would've been figured out before he got stabbed, if Ezio Auditore wasn't a completely terrible assassin.
So my boss is actually a nice guy who pretends to be evil in order to screw over his conspirators. I guess that's good? He's not really a bad person, he's good underneath. He hurts me because he loves me. And when I break through that rough exterior, I know I can change his beautiful soul.
/joking
//although Tarek is a handsome man
///with creepy cat's eyes - that never gets addressed in the game