My Little Pony: FIENDship is Magic

My Little Pony: FIENDship is Magic is a miniseries from IDW Publishing that ran during April of 2015. It consisted of five issues.

Synopsis
Each issue consists of a self-contained story detailing the origins/history of various antagonists from the first four seasons of My Little Pony: Friendship is Magic and My Little Pony: Equestria Girls - Rainbow Rocks. The first and last issues involved in company with one or more friends learning the story of a particular villain from written or oral accounts. The middle three issues all launched immediately into events 1000 years or more before the present day of the Friendship is Magic series.

Successor
FIENDship's run began and concluded during My Little Pony: Friends Forever's run. After Friends Forever ended, the next miniseries was My Little Pony: Legends of Magic. Somewhat sadly, Legends of Magic-in conjunction with Shadow Play-would retcon the events of Fiendship is Magic issue 3, establishing a different origin story for the Sirens. Fiendship is Magic issue 4 serves as a sort of prelude to the Nightmare Rarity arc, while issue 5 follows up The Return of Queen Chrysalis. Issue 5 and issue 1 both serve to set up Siege of the Crystal Empire.

Characters

 * King Sombra: the illegitimate king of the Crystal Empire introduced in The Crystal Empire. His issue establishes Sombra as a tragic figure whose one friend was Radiant Hope. After learning of his true nature as an Umbrum, he chooses to embrace the dark destiny shown to him by the Crystal Heart.
 * Appears in: Fiendship is Magic #1,
 * a Centaur Lord and enemy of Equestria introduced in Twilight's Kingdom. Tirek's lust for power is shown to have begun in his youth under the tutelage of the sorcerer Sendak.
 * Appears in: Fiendship is Magic #2
 * Dazzlings: a trio of Sirens consisting of Adagio Dazzle, Aria Blaze, and Sonata Dusk, first introduced in My Little Pony: Equestria Girls - Rainbow Rocks. These villains use their musically-based magic to drain magic from to increase their own power.
 * Appear in: Fiendship is Magic #3
 * Nightmare Moon: the corrupted form of, banished to the moon by as discussed in Friendship is Magic. In events touched upon in the Nightmare Rarity arc of the Friendship is Magic comic series, she establishes a dominion on the moon and corrupts the native Nyx into her Nightmare Forces.
 * Appears in: Fiendship is Magic #4
 * the queen of the Changelings, first introduced in A Canterlot Wedding. Cruel and calculating, Chrysalis' history as a would-be conqueror is revealed to predate her attack on Canterlot by over a thousand years.
 * Appears in: Fiendship is Magic #5