It's a blazing duel between two swordsmen! One of these swordsmen can cast magic, and that's the swordsman that's going to win this fight. Aguro may get that first strike in, but that's all he's going to get in! One helping of the Djinni Scorch's Stun and the swordsman'll have no alternative but to suffer Garet's blistering offense - and while Aguro's physical defense is pretty admirable, Garet has fine enough magical attacks to render that defense completely and totally useless. A purely physical fight is just the sort of duel Garet's made for, anyway, and his advantages simply cement the match in his favor. Grilled green-hair newt, anyone?
