Persona 3 final boss, 13 forms (that all look exactly the same), ridiculously long and 3 times in a row now it's got a lucky critical hit on me in it's final form killing the main character in 1 hit.
Several problems with this:
1. Why does the main character dying = game over? I can revive the other characters, why not him?
2. 13 forms? really? and they didn't even bother changing anything but his attacks.
3. Long boss fights in turn based games are always stupid, there's always a point where it stops being fun and just ends up as clicking random things from a menu seeing what makes the biggest numbers come out of it's head.
4. 1 hit kill moves. I'm not even talking about the critical hits, this boss has 2 forms where it just spams instant kill moves. at no point should a game ever cause a game over because of random chance like that