Sauron (Fellowship of the Ring) vs. Voldemort
For some reason Voldemort is locked into a room with Sauron that is 50 feet by feet of indestructible metal. The dorrs only unlock when one kills the other by destroying their body. So as for the purposes of this thread you don't need to destroy the horcruxes or destroy the ring.
Basically destroy the other's body and you win.
Who wins ?