Huh, very interesting.
I don't often give my trolls psychic powers, and if I do, they're not all that clever. No funny little drawbacks or anything like that. Well, that's not counting the fact that one of them messed up big time and basically replaced his power with OWBURNINGPAINS!! upon himself.
That's what you get for playing with fire. Or, you know, a blowtorch. And not wear protective eyewear.