Holydude said: awwp she broke him.... must'a done some of that fancy flying like a fighter pilot
I think is because he is simply not use to flying, even Reimu complained that he can't fly. I don't think that Aya can fly at full speed with so much weigh.
I'm not sure if there's is any magic like that in FF XI since I don't play that MMORPG but in Final Fantasy series there used to be a magic called Float. I'm sure that if someone teachs him he could fly like many Gensokyo residents.