Muzan had told the uppermoons to watch over you while he was gone. And you had time to explore the infinity castle.

"This will just be a waste of time." Kokushibo said.

"Then let me try to babysit them!" Douma said 'confidently'.

"Your just going to absorb them dumbass." Akaza said with a annoyed voice.

"Bet he will." Gyutaro said along with Daki.