Dancing partner of the underworld

There were many strange phenomena in a building without a basement. There would always be sighs or loud footsteps coming from underground, a bloody handprint on the door, a dead cat with its intestines cut open, a corpse that had been dead for half a year embedded in the wall, cries for help, and a room with a legend... Who lived underground without an entrance? Who was playing tricks? Was it the legendary man in black with a black top hat, or the gloomy head of the building, or…the ghost who was persecuted to death?？