Makai Island

Island Of Hell ( 魔界岛 - makai tō)'' is the haunt of Ghosts Saints. They are drawn from the bottom they were banished from the sanctuary, ten years before by the former Pope who disapproved of their methods.''

This island is surrounded by high cliffs at 90 degrees making access difficult for intruders to the sea, but it seems likely that the  Ghosts Saints have underwater tunnels to enter and move within, as suggests the scene where Geist calls in a cave adjacent to a pool of water. Cliffs in question and the perimeter of the island is populated by swarms of biting insects intruders from all sides, and the interior of this place is ideal for a vast swamp ambushes. At the heart of the island lies the castle of illusions remains of Geist.