EUF superpowers? I'd probably choose telekinesis and/or teleportation... just to mess with girls in creative ways. Then again, "uncreative" ways are fun too.
Some girls would find an uncomfortable pressure against their pussies as their panties were pushed into deep camel toes. I'd try to appear disinterested as they began to squirm in confusion. While the girls debate how to delicately fix their predicament, I would be not-so-delicately force-feeding their nether lips more and more panty fabric!
Other girls who are rockin' round bootys would be given a fun game--well, fun for me. I'd teleport a dime down the back of their panties. Then, another... and another... When might they notice? Watching them try to deal with this strange, new problem would be entertaining to watch! Would they try to play it cool? Make a scene as the pile of change grew heavier against the crack of their asses? Whatever the case, they could keep the money they find.
Then, of course, there's the good old-fashioned burst the button and zipper of their pants! The surprised reaction! The revealed panties! Yes!
So, there you have it!