Beggars can't be choosers as I always say. However, if the tie breaker were up to me, I think I'd lean slightly more towards Fantasy. Although, if you still wish to do Sci-Fi I'd be completely open to the idea of someone being from a parallel universe or a time traveller journeying between worlds. On a more unconventional note, how about a robot who's been rebooted hundreds of years in the future, or perhaps a wealthy noble family who's been cryogenically frozen and unthawed at a later date? Or maybe a Mage who's attempt at controlling time has backfired and trapped them in the past? Only due to their extensive research in the present they're actually well versed enough to make surviving entirely possible. That is until they can find a way to undo the spell... but if they're enjoying themselves who says they would even want to go back?