The Forbidden Flame (忌火, imibi) is a sacred fire watched over by the Flamekeepers of Mt. Hikami, which was believed to defend the mountain region against black water. It was kept in the Hall of Fire and the special priests watched over it at all times, ensuring it would never extinguish. It was also used to make the Purifying Embers that can cleanse characters who have become tainted by black water, and to ensure the priests who worked with the black water ink to create reliquaries would not be harmed by it. All of the lanterns at the Shrine of the Ephemeral were kindled from the this flame, and purified the water as it flowed down the mountain.