It's stated many times that because you can't choose your power, you might not want to risk it just in case you get the worst power of all . . . self-destruction. This power is seen in action only once, when a masked man takes power in the hopes of stopping Art at Biggie's party. Oddly enough, there are a number of animals in the wild that can explode; however my own personal theory is that this power stems from the colobopsis explodens, which is an ant that sacrfices itself for its colony.