Yeah... I've heard of quirks back home with a similar function... Maybe not that prayed on fears, but at least one where the person would instantly know things about the people she looked at, including weaknesses...

[A quirk that All For One could possibly be holding now...]

I imagine whoever decided to do this could very well do that. Blackmail, or potential counter measures against specific enemies...

[And god... now that he's said it out loud he can see connecting strings that make the hair on the back of his neck stand up--and he quickly drinks the rest of that orange concoction in his hand. Shit.]