Aldon
The Shadow King's one true heir. His son.
He sits on a bench in the Son's Room of the Accursed Den, pudgy and arrogant, gnawing human bones. The masked Seer who hired the players warned: "I fear Aldon may be unwilling to leave this place."
He has been corrupted by the den. A bullwhip with cryptic runes (d4 base + d4 necro-plasmic shock damage) hangs on his wall.
The Eye-Socket Key
The Son's Room is sealed by hereditary blood. In an adjoining Statue Room of the Accursed Den stands a "black statue of the one-eyed King Lenard II" — "obvious cavity where the eye would be. Investigation reveals bloodstains in the socket." Place an eye in the king's socket and the door to the Son's Room "opens with a loud crack."
Lenard II was a one-eyed monarch of the Shadow King line. His statue gates his descendant's prison. Whose eye fits, and what bled into that socket before, is not written down.
Shadow King, King Lenard II, Accursed Den, Fletcher, Rotblack Sludge, Palace of the Shadow King
Aldon has no stat block — players who try to extract him face an unscripted social/violent encounter. The runic bullwhip's origin and its connection to the Shadow King line is unwritten. Whether Aldon, once returned, can ever rule sanely is left to the GM. The full lineage between Lenard II and the present Shadow King is unwritten.