The Caldera of Souls

It appears in the alternative timeline Spirits of Fire.

History
After the destruction of Maj'elka, the Immortal Shamans start a ritual in the eastern mountains in order to rip the world open, causing a great eruption and chaos. The shamans have used a number of fire creations to fuel their rituals and guard their rear, however the Traveler has carved a path through them. The shamans are confronted on the mountain peak thereafter.

The Shamans try to channel their fiery spells at the Traveler, however they fall short. After they fall, they try to use the remnants of their necrotic knowledge, but they cease to exist, as the bond between the three necromancers tears, putting an end to their foul schemes.