Duel Of Dark and Light

(you may only cast a Legendary Sorcery if you control a legendary creature or planeswalker)
2 target creatures duel, you may chose the winner if you don't, the winning creature gets +3/+3 vigilance and deathouch, this Added buff stays with them even when they are not on the battlefield
we've heard these "light and dark" stories to much just tell me who dies