In the Ruins of Azarath there is a prophecy, long since forgotten.
It reads "Trigon the terrible, so mighty and feared will choose two mortal men to serve him.
One hidden in the shadows while the other basks in light.
These men will be given the chance to lead an army in their master's name if they bring him back to the mortal plane.
When the full moon is bathed in blood and reaches the center of the sky, one of the men must conceive a child with theportal, the only living blood relative of Trigon, if they wish to give passage to their master.
The only thing that can stop them is the guardian.
A monstrous deity, that the portal itself will choose for a protector.
The guardian will not only be entrusted with the portal's life, but the portal's heart."
This prophecy has long since been dismissed as nothing but an unlikely story. But the thing about stories is, the more unlikely they are to come true, they usually do.