I started a Tidus-Only Challenge, and I've thought ahead the entire time thinking about what I should do at different parts of the game (Its been helpful so far) and I thought of something very bad. When you fight Seymour and he summons Anima...
Does Pain always instantly kill you, do you need death-proof? Or does that part make this challenge impossible and force you to break the rules?
EDIT- Actually if anyone knows the HP of Anima then maybe you can kill it with Blitz-Ace?