(the uppermoons and muzan where all out looking for the blue spider lilly when they where a tracked with a poison tgat stoped then from healing and using there full strength, so they slayers a tracked them. The uppermoons and muzan won the fight but they where beaten up and loosing allot if blood when they nearly all fainted they stumbled across a place with huge walls around it, that was the last thing they all saw before blacking out. Ps. You are the younger sibling to muzan who was missing)