I'm surprised no one has thought of this yet.
It's Demon-Slaying Specialist vs Monster-Slaying Specialist! Who takes the win?
Round One: Pre-Berserker Armor Guts (with Dragonslayer and full arsenal)
Round Two: Berserker Armor activated (might be a stomp, if it is, just ignore it)
No prep, no knowledge, both going for the kill. Guts is alone.
Fight takes place in a castle.