Upon casting this spell, you conjure up a gigantic moon and set it to fall down towards the plane where you cast this spell. The moon will make impact precisely 72 hours after you cast the spell, on the exact location where you cast the spell, and at that moment, you will be teleported away from the plane (as if you had cast plane shift) and all creatures, objects, and entities on that plane will be completely and utterly obliterated. There is no saving throw, no spell resistance, no protection, no immunity; when the moon falls, everything DIES. You are not in danger of being directly flattened by the moon you summoned, even if you are in the exact same spot where you cast the spell at the moment that the moon makes impact; you'll be teleported away before you are actually harmed. Of course, conjuring up armageddon is physically draining, and the act of casting this spell inflicts 21d6 backlash damage, 4 points of Constitution burn, 3 points of Wisdom burn, 2 points of Dexterity burn, 1 point of Strength and Charisma burn, and a 24-hour −1 Intelligence penalty to you. (The ability burn and Intelligence penalty are inflicted upon all spellcasters who contributed to casting this spell's casting; the backlash damage is inflicted to each spellcaster in an amount proportional to the level of the spell slot contributed, as seen in the factors list.)
There are only three ways to stop the moon; killing or KO'ing the primary caster of this spell (as in, the being who actually cast this spell, not the 63 other spellcasters who helped him or her cast it), destroying the moon, or catching the moon and flinging it into outer space. The moon is a Colossal++++++++++ object with 5,000 hit points, +120 natural armor, and hardness 200, so it won't be easily destroyed, and catching it without dropping it, let alone throwing it into orbit, will require more strength than any single being possesses. As for the primary caster, getting out of dodge is easier said than done. While the moon is falling, the primary caster cannot leave the plane where he/she cast the spell by any means until the moon makes impact; as a side-effect, he/she can't teleport either (since teleportation involves instantaneous travel across the Astral Plane). Only by stopping the moon or the moon making impact can the primary caster's ability to teleport be restored. Furthermore, when the spell is cast, and every 6 hours afterwards, all epic-level creatures on the doomed plane and all directly connected planes get a telepathic message informing them that the spell has been cast, who cast the spell, where the primary caster is (as discern location), the remaining time until impact, and precisely what will happen if they fail to stop it (the last signal, occurring 72 hours after the casting of this spell, instead informs creatures on adjacent planes that the plane has been destroyed and where the primary caster plane shifted to; creatures on the destroyed plane are dead, and thus don't receive a signal). (See the Great Wheel on page 153 of the Dungeon Master's Guide for a rough diagram of what planes are connected to what other planes in the default D&D setting. The spellcasters who contributed spell slots towards this spell's casting are spared from the discern location effect.) This will inevitably lead to a cavalcade of deities and epic adventurers hunting the primary caster down to slaughter him or her, for a wide variety of reasons (heroism, protection of cosmic balance, simple self-preservation, etc.). The 72-hour grace period is also more than enough time for the doomed plane to be evacuated, as creatures other than the primary caster (including the spellcasters who helped the primary caster cast the spell) can enter or exit the plane by any means available to them. If the primary caster is killed or KO'd, the moon dissipates to nothing in an aurora-like display of rainbow lights. If the moon is tossed into orbit, it simply dissipates to nothing at the end of the 72 hours.
If this spell is cast on a multi-layered plane, such as the Abyss, only the layer on which the spell was cast will be obliterated when the moon makes impact; other layers will be safe. However, all epic creatures on the other layers of the plane will receive the telepathic signal of the layer's impending doom, as well as which layer is doomed.
This is the signature spell of the artifact Majora's Mask, an intelligent artifact which is actually a horrifically evil entity who loves casting this spell for sh**s and giggles. Casting this spell through Majora's Mask negates the need to make a Spellcraft check, burn XP, expend material components, or get other spellcasters involved, and Majora's Mask itself is considered the focus component of the spell. However, casting this spell through Majora's Mask still costs a creature 4 points of Constitution, 3 points of Wisdom, 2 points of Dexterity, and 1 point of Strength, Charisma, and Intelligence, which can only be recovered through natural healing (or penalty removal in the case of the lost Intelligence). While the current wearer of Majora's Mask will be treated as its caster, thwarting the spell if he or she is killed or KO'd, destroying Majora's Mask itself will also thwart the spell when Majora's Mask casts it. (This is a mercy to the caster, who will more likely than not be possessed by Majora's Mask.)
