Ashurak, the Slow Death is one of the Overlords who ruled over all of Eberron during the Age of Demons. Ashurak was bound by the dragons and couatl after they jointly discovered the Draconic Prophecy, and the couatl sacrificed themselves to form the Silver Flame.
Ashurak is the patron of the Plaguebearers, and lives in the horror of disease and infection. Their infections cause horrifying pain and disfigurement, and eventually death, but never quickly. Ashurak brings only slow death, and revels in suffering that persists and lingers. Their diseases can even render a person something akin to a zombie, their mind overtaken with nothing else but the desire to propagate the infection, though they are not undead. Some believe these poor individuals are still conscious and aware.
They are bound within the Demon Wastes, and the region around their prison is festering and desolate. The Plaguebearers make their home there, drawing and cultivating diseases from Ashurak's prison, and spreading its influence to any they encounter.