Charlotte DeBel
White Queen of KMC
Well, Dante in his prime (DMC2) has developed strong resistance to "instant kill" demonic magic based spells (the knock down in the first fight with Mundus doesn't count- see above with experience gap). The manual to the game and the one on that version of Dante "exported" into Nocturne (statswise Nocturne is canon, as stats were approved by Capcom being the same as in DMC2, but storylinewise SMT:Nocturne is one huge fanfiction of a game).
Dante isn't genius in sence of being uberwarlock\scientific sence, but his talent to improvise is second to none, "everything goes as a weapon" is his motto, and that (as was written above) gives him the chance to close the experience gap.
Sparda\Super Sparda form has all the things associated with high level demons like conjuring up meteors\fire dragons, instant death blasts (though their oneshotting everything properties can be partially gameplay). Powersetwise it's not that inferior to demon lords in Warcraft, probably in size (high demonic form (Sparda form) is only about 3 meters tall, size of 2 store building as seen in DMC2). Experience is the thing, though.
But the fight I'd LOVE to see is Dante vs Illidann (spelling?), later being the only character in Warcraft I do care about.