The Spirit Room was created by two High Rankers, Grand De Jah and Grand De Sah with a special Spell and stored all the souls of the 43rd Floor's inhabitants on the three waterfall structure. While all souls are placed on top of the waterfall, Po Bidau Gustang actually hides and sealed the Second Thorn Fragment deep inside the inner foundation of the structure. Ordinary people can't enter the inner foundation because of the powerful pressure and thick density of Shinsu flowing inside.
After Enryu killed the 43rd Floor Guardian, most of the people on the 43rd Floor died because there is no Shinsu since the Guardian had died. There are few strongest Rankers who survived with the unusual shinsu, aging, and lack of food. To make matters, worse, rumours began spreading about a Thorn that Enryu left behind that was capable of killing King Zahard along with rumours about Enryu's abilities himself. To stop the rumours, the Zahard Family dispatched an army to block all entrances and exits while killing anyone who are trying to leave in order to prevent the rumours from spreading. To end the situation, Grand De Sah and Grand De Jah used magic or Spell to create a 'Spirit Room' to store the souls of all those residing on the Floor. In exchange for being unable to leave, the Floor's residents would have immortality.