Just a quick question; does anyone recall having seen an enemy holding a Spite Pouch? The data would suggest they can, but I tried for a long time to get the 4-Dry-Bones group inside Hooktail Castle to hold one, to no avail (I tried a couple dozen or so sets; the odds of me seeing one in that time were ~99.5%). We know from experience that an enemy can't hold but a certain few items in battle, even if they have a hold chance for them, so maybe Spite Pouch was a miscode on one end or the other.
In any case, the reason I asked was that I wanted to test whether having Payback status made you invincible to enemy Payback status, or vice versa, sort of like Electric. I guess you could test on Poison Puff, as its charged status seems to be handled the same way damage-wise, but there's no guarantee that works. Grodus is the only enemy I can think of that I know for a fact uses the status, but I don't want to bother with that at the moment. Maybe if my roommate finally brings his Wii to my dorm, I'll play through to that battle on my file (I still haven't beaten the game quite yet; pretty sure I stopped about half an hour short of there).