Imagine you're introduced to someone who was faced with it and who slit the fat man's throat without blinking. Would you feel warm and fuzzy about this person?

I'm not sure "warm and fuzzy" is the right term, but ... I would feel a certain respect, and of course update my probability that they will fail to take the correct action out of bias or akrasia. And my probability that they will kill me.

Would you be creeped out by someone who cheerfully admitted they would kill you if you turned evil? I mean mind-control type evil? Because in fiction at least that's treated as a good thing, but still creepy.

(I think the creepiness is the fact that they can and will kill people, and there's the ever-present worry they might mistake you for a risk.)