The large comb, white ear lobes and aggression might indicate there is some Leghorn blood in there, but agree he looks a lot like a Bielevelder, so maybe a Bielevelder/Leghorn mix. He is very handsome but it's not good that he is aggressive. Personality should count for more than looks when keeping a rooster in a backyard flock and if he would not retrain, then he would make a good chicken dinner, albeit a bit tough at his age.
Not a cream Legbar.
Actually Welbars should have red ear lobes according to my research.