@Whoami - I'd suggest simply writing a character that you'd be happy with even without any powers, that way your aspect will be just a cherry on top. That said, a few suggestions...

*I don't think their are any gas stations to crash into, since everything runs on duskstone.
*Not sure about 'high school'. Education doesn't seem standardized or mandatory, more like a privilege for the wealthy.
*I'd shy away from the seven deadly sins bit--at least until Mancala weighs in on what religion prevails in the setting
*Killing hunters--even indirectly--seems like the sort of thing the fraternity would come down on -hard-. Internally if not officially.