I don't have a problem with mind control if it's effectively being incredibly persuasive. It's weakness would be that when it gets seen through (as in the decisions they are feeding you are figured out to just put them in a better position) then it loses all effect. That doesn't mean that you can't have it used on you again, but your character will then be questioning every move that they make to try and find out if it is actually their decision to do something.

As for mindfrays.. whats the actual logic behind them? Because if it's a headache that gets worse the weaker their target is, and effectively acts like a debuff, then I'm all for that. It'd need to take quite a bit of concentration to use though: you can't use it while doing something else at the same time.

So then effectively, that kind of character would find a place to hide, and make another character their "champion", feeding them thoughts that keep them away from them and on their side, while mindfraying everyone they fight to give them the best chances.

To balance that, they'd probably have to be mediocre at actual combat?