This story is a sequel to In Want for a Wand
On his search for Twilight Sparkle, Darren Houndslayer discovers King Sombra's horn and unwittingly resurrects the tyrant. He soon wonders if it might be better to reform an evil king instead of killing him for good. Darren struggles to find his place as a former Death Knight in pony society - but he finds himself confronted with his past by a young colt who develops dark powers that are disturbingly alike to Sombra's...
4th installment of the Twilight Goes To Dalaran series.
Knowledge of World of Warcraft is not necessary to understand the story.
WARNING: Spoilers in the comments!