The ability to nullify others' special powers.
Invisibility. I don't think I could possibly use THAT power for good. ;)
Monkey D. Luffy's ~ !!! "Gomu Gomu no...."
The ability to ban this repetitive question.
Ha, sorry, I'm a sad bas@rd and have seen thousands of questions over the last three or four years - no insult intended. I just get a bit gobby sometimes!
I want Mystique's powers from X-Men, I don't even know if thats how you actually spell her name haha