After guytaro and Daki have been killed you have been summoned into the infinity castle along with the other upper moons

When you arrive Nakime, Akaza and Gyokko are already there

Akaza: Where is Lord muzan? Nakime: He will arrive shortly.

Gyokko: It's been sooo long sence we've been last summoned here!

You hear hantengu from the corner Hantengu: S-So S-Scary!