Super Hero

Question of the day is, if you were a super hero, what would you be?

Rules:
Pick a power. A power will be defined as a special ability that can selectively void or add a law of physics.
Pick a setback of that power. Whatever it is, give it a limit or an exception. It should make sense.

Examples:
Super Bagman!
Master of disguise, can change into any shape, living or not, emulate any voice, emulate any physical property, anything. Perfect copy of the original. Problem is he can only do this for 30 minutes at a time.

Flipsy!
Telekinetics have never been so easy. Can move any object all 3 degrees of displacement, and all 3 degrees of rotation. Problem is that he ages at an accellerated pace when doing this (4 times as much) and if using this ability first thing in the morning, he can do only about 9 hours in succession before he goes unconscious due to exhaustion (equivalent of staying awake for 36 hours).

Craig!
Can fold his tongue to look like a clam. Problem is doing so will cause explosive diarreah.

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