There's no way they could make this work (and be both challenging and fun) letting us use our real abilities.
I could see it working using the 'roleplaying' feature, like the recent Hien, Y'shtola or Alphinaud battles, where the person we're controlling has fixed stats or moves.
Or what I'd kill for - make it a turn-based, menu-based RPG minigame, more or less exactly like FF7...