(one sec while I google that character name) I'm... guessing what he "does to himself" is like that stitching down the throat? That doesn't sound like anything we'd have a problem with, but I say that tentatively because I'm canonblind and have no idea if that example had a bigger significance than I'm realizing.

Assuming your question is in the realm of "can I use this event to make my character more sparkly and keep them that way later", there's no harm in that. The intent is to give players the opportunity to let people go wild with crazy monster stuff on a temporary basis, but if you want to hold on to a couple of extra noserings or whatever, that should be fine. Mark your character up as much as you want.