Yoriichi himself has shown that he can single-handedly kill Muzan in an encounter between the two. The only reason the latter survived is that he split himself into thousands of tiny pieces to escape.

The fight that will surpass the Muzan vs Tanjiro battle is the one involving ... We can see Kaigaku’s frustration build while Zenitsu evades his attacks with relative ease.

The Infinity Castle movie will be a trilogy set within the eerie, labyrinthine structure of Muzan Kibutsuji’s abode. In this vein, the castle is a stage for monumental battles where the demons ...

We then see flashes of past Demon Slayer Corps characters and Hashira. From there, we see Tanjiro fighting alongside a number of the Hashira as they all move to attack Muzan at once.