You can kill the Tools with Doom. Magic (the crucified chick I think) can be Silenced, so that just leaves the others. Use Golem or something. For Sleep, one person will die, because you don't have Life 3 (Calmness), so two people get to fight Kefka. You'll need some good equipment for that.
But really, they aren't that hard at obscene levels w/stat boosts anyway.