How to beat Sephiroth in Kingdom Hearts??

Du are talking about Kingdom Hearts I and not II right?I will give Du both answers.First Du must have plenty of Elixirs oder Hi Potions with Du because the "Descend Heartless Angel" Bewegen leaves Du with 1 HP and no magic!!!No magic means no Cure and no Cure means no Mehr HP.You can stop his spell before he casts it Von hitting him!In Kingdom Hearts II Du need the Aerial Dodge ability (you get that after leveling Master Form [Master Form levels up when Du get Drive Orbs]) to reach him.In Kingdom Hearts I Du must be lucky enough oder Sephiroth be fool enough to teleport behind Du before he cast the spell.If he casts the spell go away from him as far as Du can and give a Hi Potion to yourself.Better have it in the shortcut menu.Hope I helped ;)