SPELL-HOLOCAUST
In the Third Age, there was an accursed cult of powerful wizards who were dedicated to the ultimate destruction of the universe. They believed that in the destruction of the universe a new cycle of existence would result. They worked and devised many terrible spells in order to bring this annhilation about. Their early works, "inferno" and "solar gate", while causing great pain and sorrow, did not approach their goals.
The leader of the cult, The One Whose Name Is Not Spoken, however, devised such a horrible spell that even the mightiest of the Gods of Darkness knew mortal terror. Its casting of the spell, 'holocaust', rocked the universe with such terrible pain the likes of which it had never known. Many of the lesser gods were slain and whole civilizations ceased to exist.
The spell did not, however, bring about the destruction of the universe. So the accursed wizards continued their work with renewed vigor.
The Gods of Light and Darkness drew together to purge the cult. But the cult was strong and slew many gods. The Highest Gods then sought to create a being terrible and mighty enough to end this arcane plague. Many lesser gods were sacrificed, with their souls fused into the new creature. The creature was given the name Bal-Zur. After a great battle with the accursed wizards, Bal-Zur emerged victorious.
The gods then searched for all copies of the accursed spell and destroyed all that they found. It is not known whether any copies remain, and no known wizard knows the invocation. The Gods then declared that any who managed to find and invoke the spell would be dealt with by Bal-Zur.
It also is rumoured that the invocation of this spell may crack the world (read: "crash the mud" or ask Odin for the 28 reasons not to cast it). Save versus fortitude for half damage.