When a player is unlucky, a blood moon won't arrive even after WoF defeated. So if blood moon loot is wanted, we need to farm the bride and the groom in a graveyard, but they are so rare, even sleeping in a full-spawn rate pre-HM FTW mob farm, it's possible that in hours, no bloody tear will drop and no blood moon will arrive. So I recommand to rise the spawn rate of the two mobs in graveyard.