The Prophecy of the Demon Messiah was a prophecy Sar-Shazzar had made centuries before the birth of Sareth, the half-human, half-demon offspring of the Demon Sovereign Kha-Beleth, known as the Dark Messiah or Demon Messiah.

The prophecy is fulfilled when the Dark Messiah destroyes the Skull of Shadows, the last remains of the Seventh Dragon after Sar-Elam's sacrifice to seal the inferno that is Sheogh, rezulting in the freedom of Sareth's father and the busting open of the gates of Sheog, dooming Ashan forever.

This is a prophecy Arantir is bent on preventing at all cost by slaying Sareth, whom he did manage to kill in 989 YSD, but being unable to finish the job as Sareth is reborn by Xana as the half-human, half-demon heir of Kha-Beleth.

The Prophecy goes as follows
Ten centuries shall the fortress stand
Walls of spirit wrapped in walls of fire
And horned lords shall bowl their head
To one not yet born, of the darkest sire
One century of blood and strife
The moon shall darken, and none know why
The resting place at last is found
Of the Seventh, who soared so high
Last daughter of a forlorn line
Shall guide him into history
Beneath the crypts prophecies clash
The war of ancient enemies

Should the Prophecy backfire upon Kha-Beleth when Sareth, accompanied by either Xana or Leanna, chooses to finish what the Seventh Dragon began by keeping the Skull and using it to seal Sheogh once more, locking the Demon Sovereign back, he shall forever curse the Dark Messiah and his mother, Isabel Greyhound, for failing him, branding Sareth as a traitor who "grew as weak as [his] mother", vowing to hunt him down "like the cur that [he is]", promising that one day, he shall be free, and shall show Sareth the full measure of agony.

Thus, another part of the Prophecy will be read, saying:

From greed or fear, it will decide
The Chained One is left alone,
The relic's power, yet untapped,
And Ashan's fate still yet unknown.
Community content is available under CC-BY-SA unless otherwise noted.