The Map Guardian Ghost is an entity tasked with guarding the Map to Nikulausson's Tomb.
After Kylie Griffin, Rookie and their guide entered a cave in the Aokigahara Forest, the ghost sensed their presence. While Kylie retrieved the map, the ghost possessed the guide. It told them only death would come to those who would take the map. Rookie demanded it to release the guide and fired his Particle Thrower. The ghost gave them a choice: leave the map or die. Kylie admitted the ghost won and promised to not only leave the map but make sure no one would ever find it again. She threw it onto Rookie's Proton Stream. Kylie asked the ghost to vacate the guide's body and they would leave peacefully. The ghost refused to vacate its new host. Kylie opened a Trap and captured the ghost. The guide was still in mid-air and fell to the ground.
The ghost appeared as a giant purple octopus.
The ghost displayed the ability of possession.