don't think that just because strangefate happened to have a slave named 'mxy,' that he would automatically beat the mxy we all know and love. the amalgam mxy's best feat was what? teleportation? hell, not even strangefate himself did much at all - in fact, he was beaten by dr. strange alone in the end. pfft, give me a break.
the 'real' mxy takes this easily.