Mawile is better. It tops Blue Eyes-White Dragon in damage and you don't even need to sacrifice 3 monsters to summon it.
That's borderline OP.
Blue Eyes White Dragon only needs two monsters as tribute.. But the real magic happens when you have tributed 6 monsters total to summon 3 BEWD and then you use a polymerization. Watch out Hydreigon a different three headed dragon will wreck your s***