For anyone who's curious it's a poly ending where butler/ demon king is the main husband and he allows not only other MLs to stay but for them to sleep with FL too. Butler even goes away for a few days and comes back to FL covered in Semen having an orgy with the other guys. Btw FL planned the whole trapped in the mansion thing with the butler before the soul swap due to not wanting her fiancee to keep hating her and her childhood friend to distance himself (she wants both of them to be hers lol), not too sure what's with the priest.
Also FL swaps souls again and does go back to her world and she keeps in touch with the OG Sera (she asks Sera for advice on seducing a dude back in Korea)