You were travelling into Muzan's infinite castle, the place was like a labyrinth with no exit, at some point you see multiple butterflies flying around and in the distance is visible what looks like an exact recostruction of the Butterfly Mansion who was owned by: Shinobu, Kanae, Kanao, Aoi, Sumi, Kiyo and Naho.

The main door of the mansion is open and nothing is visible thought it from the distance, do you dare to enter?