fervent ridge
The requirements should be killing 100 demons per player and a minimum of 8 people (2 people with Each upper moon) (feel free to add suggestion for the requirements for the infinity castle)
It should start off as doors appearing under you making each player fall with a cutscene of them falling, after it will be you and someone else moving in the infinity castle fighting weak demons until eventually each player encounters a uppermoon (1,2,3,4) the bosses will all have different moves and abilities and will also be harder depending on the uppermoon that you fight. Afterwards when they are all defeated the players find muzan and they all fight him together until he’s dead.
The rewards should be getting the clothes of the upper rank you killed. (idk I couldn’t think of something better leave suggestions of better rewards)
digital bloom
hoary mural
hallow cradle