Tul Oreshka embodies our fear of secrets and the things we don’t know, of unbearable truths and feelings we’d kill to keep private. These may be deeply personal—“your mother wishes you’d died instead of your brother”—or shocking cosmic revelations. She’s far more primal than Sul Khatesh; the words she deals with may not conjure fire or fiends, but they still have the power to shatter lives. People who pass by her prison may learn terrible things through ghostly whispers or vivid nightmares. Though her cults take many forms, they’re almost always driven by a compelling, infectious idea. While she doesn’t deal in traditional mystical knowledge as does Sul Khatesh, Tul Oreshka can reveal secrets that defy our previous understanding of magic or that alter the way we see reality. For example, a cult of Tul Oreshka might reveal that humans are actually fiends—and humanity itself is collectively an overlord.
While her agents are unpredictable, Tul Oreshka does
participate in the Bleak Council of the Lords of Dust; her
current speaker is a pit fiend named Korliac of the Gray
Flame, though Tul Oreshka’s speakers rarely hold the
position for long. The location of Tul Oreshka’s prison
has never been established.
Source: Chronicles of Eberron
Fearsome truths hide in the shadows - the hidden thoughts of those you consider your friends, the terrible deeds of ancestors, the moment of your death. Tul Oreshka embodies those horrible secrets. Her actions are never predictable, and she as much of a threat to her allies as to her enemies. Anyone who passes by her prison might suffer nightmares or hear terrible things in ghostly whispers, and children born or conceived near her tomb are always insane. Heralded by a wave of madness, her release would shatter the minds of all those who dwell near her tomb.
Source: Dragon 337