Istrakath
"A largely forgotten demon, despite his high rank, much about Istrakath and his origins are unknown. What is on record about him, indicates that he prefers to spread chaos and mayhem through disease and other bodily ailments. Victims of Istrakath often developed severe disfigurement of the face and body, even growing additional limps, as well as painful skin conditions and lesions. Mercifully, these are all temporary conditions as once the Duke is purged, the victim makes a full recovery.
It is speculated that Istrakath was disgraced by his master and his followers exterminated or disbanded entirely, hence the lack of any written record or oral history surrounding the Duke, but there has been no way to verify any of these theories."