Maruo is a strong hand to hand fighter. He gets more powerful with every fight and is definitely a lot to handle. That being said, Asta still has the advantage here. First off, having a blade is a huge advantage in any fight and he’s also shown to be way faster. Maruo barely had time to get too many developments in his power level before the series was cancelled which puts him in really hot water against someone like Asta. Asta wins.