Neither of them dies but spectre is at the advantage here simply because if Mordru beats him he still looses in the end due to that aoe magic drain spectre pulls. Mordru definitely puts him down first though but Spectre doesn't stay down long enough to count for a win and promptly drains Mordru to nothing. Mordru put down the prepped shazam like Rocky Balboa would a dying puppy with the punch that leveled Drago.