Devlites, Dialantes, Dialicies
A pagan giant who ruled in the Distant Isles in the time of Joseph of Arimathea.
His sons all converted to Christianity, so Dialetes killed them and every other Christian he could find. He built the Castle of Tears on the Giant’s Isle as a stronghold against Christianity, which retained its evil customs until destroyed by Tristan.
This account first appears in the Prose Tristan; La Tavola Ritonda expands on it and asserts that Dialetes slew Joseph of Arimathea himself.
Sources
Prose Tristan | 1230-1240
La Tavola Ritonda | 1325–1350