Something that came to mind, why not have one of the alien races use telekinesis in Battle?
Instead of the usual rifles they could have a kind of pellet ammo that works especially well with TK to achieve
good damage, like a mini plasma grenade that would function the same as a shot from a plasma rifle.
Instead of the usual mind control/panic they could suspend a target and prevent movement, or be tricky and
disarm the target or drop the clip out of rifle that's being aimed at them.
For harder difficulties they could just pull the pin on a grenade that's being carried by one of our soldiers, though that's probably a bit too evil.
Any thoughts from someone else?