All lower and uppermoons have been killed by the Hashira's as though a few Hashira's have been killed as well. Muzan, had been fighting the Hashiras for a while in the mix of being trapped in a bloodlike cage that stopped him from moving. Soon the strongest Hashira Gyomei, slid into battle swinging his spiked flail on a chain. Before aiming it and swinging at Muzan

Muzan turns to Gyomei's attack in anger, while you also being the Lord of Evil and Muzan's creator had watched in annoyance