Big brother
OH GOD THIS IS SO OLD D: I'm only putting it up because I kinda like the concept. Zidane and Vivi's relationship is so adorable, with Zidane being like a supportive, protective big brother to Vivi, without being actually over-protective or mollycoddling - instead of trying to keep him sheltered from all the "evils" of the world, he does his best to encourage and empower him to face them and get stronger.
Uh...yeah.