Sheik has successfully willed himself to stay sane, but is still affected by the bimbofication.

What neither Tiff nor Impa in her bimboed state knew was that Sheik was really Zelda, and as such still carried with him the Triforce of Wisdom, which offered some level of protection against spells and curses like this. Well, like, crap, Sheik thought to himself. I'm like, still me in here, but even with the Triforce-thingy it's still kinda hard to think. What am I gonna do here? These two dumb bimbos are gonna totally try and turn more people, I swear. I can't like...let that happen? Right? Sheik looked down at his transformed body, at the large breasts peaking through his jumpsuit, and idly started twirling his hair with one finger. Then again, like, why wouldn't someone want this? I know they wouldn't, I think, but why not? It's pretty cool.