Actually... Never mind what I said in this post originally, his FFVII wait would be fine with me.
But, most of his animations will transition oddly... You would have to go back and fix a bunch of animations... I'm honestly fine with his current one too, so do what you feel is best.
(But still don't forget to fix his air movement, as SDo0m said, it's like Mastaklo's Shadow's, too good. And if possible, make him have landing lag like Cloud's neutral air when he lands with forward air... Although, then again, fixing his air movement might fix any balance flaws with this move, so... For now, just change the air movement.)
lol I saw that discussion between you and sdoom yesterday XD....I'll work on sephy a little more after I finish up Tidus. I'm really really close to finishing him. I just need to finish up his final smash and make room for spell cast in his specials tab

You know you can always make in increase in gravity and terminal velocity to compensate for the air moblity like how Falcon, Wolf, and Gray Fox use high gravity and terminal velocity to compensate for their high maximum horizontal air velocity.
yeah thats true. I don't remember giving sephy more air mobility now that I thought about it.