Arpian

Harpion

The Lord of the Treacherous Castle, an evil pagan stronghold, where he imprisoned maidens and killed Arthur’s knights.

He imprisoned Galahad, Hector, and Meraugis, but was slain by them after a holy cataclysm freed the three knights from their prison.


Source
Post-Vulgate Queste del Saint Graal | 1230-1240