Mordel was a character in the short story "For a Breath I Tarry...", which I found in (of all places) a psychology textbook which illustrated various concepts with science fiction stories.
Mordel is the servant of Divcom, the representation of evil in the story. His job is to convince Frost (the protagonist) to join Divcom, and turn away from his master Solcom. He becomes the mentor of Frost, showing him what is left behind of the human civilization. Mordel is the one who forces Frost back into his human body at the end, justifying it as "protecting the human race", against itself.
While Mordel worked for Divcom, he was not ruled by him. Here is an excerpt, the first time Mordel meets Frost:
"Hail, Frost! Controller of the northern hemisphere!"
"What are you?" asked Frost.
"I am called Mordel."
"By whom? What are you?"
"A wanderer, an antiquarian. We share a common interest."
"What is that?"
"Man," he said. "I have been told that you seek knowledge of this vanished being."
"Who told you that?"
"Those who have watched your minions at their digging."
"And who are those who watch?"
"There are many such as I, who wander."
"If you are not of Solcom, then you are the creation of the Alternate."
"It does not directly follow. There is an ancient machine high on the eastern seaboard which
processes the waters of the ocean. Solcom did not create it, nor Divcom. It has always been there.
It interferes with the works of neither. Both countenance its existance. I can cite you many other
examples proving that one need not be either/or."
"Enough! Are you an agent of Divcom?"
"I am Mordel."