Demon Slayer: What role does Murata play in the Infinity Castle arc?

Murata, a member of the Demon Slayer Corps and Tanjiro Kamado's friend, is a supporting character in Demon Slayer: Kimetsu no Yaiba. He joined the Corps since he had no living relatives after demons destroyed his family. He and Giyu Tomioka are both from the same batch of Demon Slayers.

In the finale episode of season 4, the Hashira Training arc, Kibutsuji Muzan pays a visit to the Ubayashiki house with the intention of killing Kagaya Ubayashiki. Ubayashiki blows up his mansion in a last ditch effort to defeat Muzan, failing to kill the Demon King but succeeding in uniting the Hashiras. The Hashiras and many other Demon Slayers ambush Muzan in an attempt to kill him. Suddenly, enormous doors beneath them open, sending everyone to the Infinity Castle.

In the ending of the episode, there was a short scene showing Murata's fate at the end of the Hashira Training Arc. While with his classmates on night patrol, sliding doors appeared beneath Murata and several of his classmates. The doors then opened without any explanation. Murata and his classmates fell into the Infinity Castle and were influenced by the strange gravity of the realm, shown to be visibly terrified.

Viewers of the anime series may be wondering what role Murata plays in the Infinity Castle arc, since many important battles are fought during the last arc of Demon Slayer. Murata doesn't fight in any fights throughout the Infinity Castle storyline. Instead, he concentrates on bringing Yushiro and Zenitsu and other warriors to safety during all the fighting. Murata also helps take care of Tanjiro's wounds after the fortress collapses. When it is revealed that Muzan has been defeated and the demons are all dead, Murata can be seen crying with relief.