Several Ability Questions

[Ansehelm]

Hey y'all, making some abilities for my mod, and I was wondering how several things can be accomplished:
-Make a damage ability that can only be used in critical, similar to fft 1.3's defy ability, but with offensive capabilities
-Make an ability that targets the caster and enemies, but not other allies, and/or KO's the caster only while dealing damage
to enemies
-I want to make an ability with the grand cross graphic that removes debuffs from allies, but I haven't been able to get it working - is the graphic hardcoded in such a way that this doesn't work?
-Make an ability that damages or KOs only units with a certaim status (e.g sleep)

I'm also experimenting with having one enemy unit crystallized/treasured at the beginning of battles in a hard-to-reach area -(by having that job class have innate crystal/treasure). The crystal works decently, but the rotation is wonky, and the treasure chest looks like a discolored chicken.  I'll experiment with scrapping the sprite for that unit, but was wondering if anyone had insight into this
Thanks