The Boss' identity was something Aria had encountered in the past.
As she thought, it was a spirit type creature as well. A 'Dealer Spirit'.
Someone who exchanges an equivalent price for the asker's wish.
In this case, the Spirit was set up for a meeting with the goblins by the 'Creator'.
In exchange for a home, the Dealer asked for their life force. In order to mobilize the dungeon, the goblins had to share their life force.
Of course, it wasn't like they would die. On the Dealer and the goblins' contract, it was stated that the 'reward' would be to provide them with a home: and that the Dealer themselves couldn't kill the goblins.
The goblins' wish had to be fulfilled, or else the contract would be breached and the spirit would suffer.
The dungeon was unexpectedly sustainable.
