The ability to create and control, to any and all extent, the following:
fire/temperature
darkness/shadow
Also, an ability to control and read minds. Basically, most of the powers fictional character I've already created have.
EDIT: Reading other posts has reminded me of more.
Extreme, rage-driven strength/power/speed, seductive/addicitve powers, the power to break a person mentally/emotionally.
So, from this list, anything driven by anger/hate/rage (i.e., the fire, the strength) or by just having kind of a sick personality (i.e., the darkness, the depression, the seduction)