The Last Writ of the Liar Prince

In the final days of the Immolation, as the united armies of Kelember's nations marched on the last stronghold of the Nine Hells, Asmodeus issued a decree. By his word he swore that he had come to the material plane with benevolent intentions. He spoke a prophecy into being of pure apocalypse, so definitive and final in its occurrence that even if the High Pantheon were free to stop it, it would make no difference.
"The Planar Gates are fragile and the sacrifice of the gods is not enough to save the worlds from a final fall into chaos. Every plane now touches the Prime Material, seeping their corruptions into the pure creation of the Yorum. If the final gate falls and the Abyss has its turn to overrun the Material, it will spell the end of all creation. Primordial chaos will tear apart reality, throw all of the planes together into a cosmic mass of energy, and birth endless demonic rule over the land. Only the Nine Hells, through our rule of the Prime Material, can prevent the fall of the Last Gate."
Arcane scholars consider this a feeble attempt by Asmodeus to wield fear as a final weapon to bring the surrender of the Material Plane as the mortal forces came ever closer to banishing him back to the Hells. Several corrupt mages had summoned and bound demons on the material planes for ages, something that should not be possible if the gate still stands. Adventurers had over the centuries found several ancient artifacts with known ties to the Abyss and several of its dark lords.
Whatever the truth of this prophecy may be, the warning has given rise to numerous cults who worship and sacrifice in the name of Asmodeus, the one true savior of mortals and the arbiter of salvation.