A butterfly managed to get into the Infinity Castle.

The three most powerful Uppermoons and Muzan himself were acting like idiots over the butterfly in the castle and Muzan was just pissed off in the corner while listening to their bullsh*t.

Akaza: "Fight me or die, creature!!"

Kokushibo: "What kind of bird is this?"

Doma: "Master, Master! Look! It's one of those things Shinobu-chan likes!"

Muzan: "You need them, Kibutsuji... Just remember that you need them.."

There was a moment of silence before-

Doma: "I'm gonna eat it!" :D