Originally Posted by
Siriel
Talking about the Fate franchise overall, both Karna and Gilgamesh agree that that Gilgamesh would beat him, which is further reinforced by Word of God. Gilgamesh also explicitly considers Karna someone worth taking seriously (when they meet in CCC, his immediate reaction is to back out of melee range and get ready to fight) so unlike against some people there's no chance he'd mess around and get himself killed.
So the matter is only hotly contested by people who'd ignore everything that's ever been said on the subject, pretty much.