"I'm a struggling artist, frustrated writer, ...
Having an IQ higher than any measurable, super intelligence, when utilized, allows the user to apply that knowledge in many different ways, from tactics to engineering.
The ability to manipulate energy, from light to heat to mechanical energy. In theory the person may even be able to create matter by converting energy into mass.
The ability to use any weapon in the manner of a master of said weapon. The user can grab any weapon no matter how esoteric and use it like they've trained their whole lives with it.
The ability to manipulate one's own hair and give it the ability to change form, grow, shrink, grasp objects, et cetera. Useful for someone who has no weapons.
The necessity of sucking blood. Usually in exchange the user gets a host of new abilities like super strength, speed, shapeshifting, and flight, but ever since Twilight all they do is sparkle.
The ability to change one's form to any other form. May even be able to change their own form into things that are physically impossible, like mist or Moebius strips.
The ability to speak, read, write, and understand any language no matter if the user would not have known of the language beforehand.
The ability to be faster than any human has the ability to be with only their own training and natural abilities. Can reach limits up to the speed of light and beyond.