Kellman

Kellman is in charge of the Demonic Academy, wherein which lies a series of brutal training programs that destroys an innocent's humanity and turns them into demons.

Kellman himself was once human and has been put through the demonic training program.

Kellman's basic duties include going after humans in need and strikes a classic Faustian Deal, promising them assistance and guidance but then the humans are lured and forced into the training academy. When the recruits graduate, they have to kill an innocent to seal the demonic conversion permanently. When they are completely demonic, they have a brand on the arm with six chevrons.

He has earned eight chevrons, which means he has completed several deeds that impressed the Source of All Evil after which he earned two more then the usual six.

One of Kellman's prize recruits was former collegiate star receiver Tom Peters. Kellman posed as his business manager, but then kept him in hiding for six years while turning him into a demon at the Academy. However, just as Tom was about to turn completely demonic, his former girlfriend, Prue Halliwell, intervened with her sisters to save several innocents Tom was trying to kill. Prue was able to stir up enough of Tom's humanity that Kellman tried to make Tom kill his own mother with a ball-blade weapon. However, Prue manages to break Kellman's hold on Tom, and Tom throws the ball-blade at Kellman, killing him.

Appearances
Kellman appeared in a total of 1 episode throughout the course of the series.
 * Season 3
 * Wrestling With Demons

Trivia

 * Ron Perlman also plays a demon/devil in the famous Hellboy movie series (who's actually its titular character and his most famous role yet).