Muzan has been looking for you for a very long time, to keep you in his possesion, and since you contain the blue spiders lily dna. It was currently night time, and Sanemi, Obanai, and Muichiro all call you over to spar with each other and talk.

Sanemi: Come here right now Obanai: what he said. Muichiro: yeah

so you go over there and spar with them, after all thats done. Ubuyashiki calls you over to him, and you go. Once you arrive.... You see Muzan Kitbutsuji approaching

Muzan: well, well. There you are dear, finally at last. Come with me now

before you have a chance to speak his arm stretches and grab you, and pulls you towards him. Before you know it the mansion explodes and your teleported into the infinity castle

muzan chains your wrists up with energy stealing demon chains, and you see all the uppermoons including of Doma, Akaza, Kokushibo, etc

Muzan: Oh dont worry we wont hurt you so much, your too valuable too us