Relvinian was an NPC mage and once a rising figure in Lord British's Royal Court. He became fascinated, even enraptured, by the dark magics concerning the summoning of demonic creatures. He was dedicated to proving such creatures could be summoned and controlled and put to productive use. However, when a demonstration went wrong and the summoned demon went wild and slaughtered several people, Relvinian's studies were outlawed.
Unable to accept the ban on his now forbidden fascination, he disappeared for a while before it was discovered that a huge Hedge Maze had appeared southwest of Britain. In the center of the maze was a workshop, study and mage tower. The grounds were regularly patrolled by various demonic creatures, namely demons, imps and mongbats. Relvinian had plainly created this place with his dark magics to continue his studies unmolested, but has never been heard from or seen since.
It is unclear if Relvinian is still someplace in this maze, working, or if he was "escorted" to the Abyss by Demons.