Fuse Abilities Submissions!

I don't think 0MP = death would change much beyond being a novelty. Not enough enemies have Rasp/Osmose, and you'd have to fail pretty hardcore to run yourself down to exactly 0MP.

That being said, I don't think either of those skills are too OP. At least, not for the endgame of FF6, where you have half a dozen other OP things you can do. The reverse debilitation would be extremely useful for challenges and whatnot, but would probably be mostly overshadowed by Ultima spells in normal play, except possibly in the final battle. As for X-Magic, since there's already a way to get that skill I wouldn't consider that to be too powerful either. We can control Meteor/Comet ourselves, so that's not an issue.