Origin stories, or just interesting stories in some of them, about the main villians in MLP.

King Sombra-really sad and depressing...and felt a bit off to me. Like it was saying you can't change your destiny but I think that's the opposite of what it wanted to say and that Sombra just didn't but it just didn't come across right to me but it was ok

Tirek-I enjoyed it well enough

I really enjoyed The Sirens and Nightmare Moon's stories and loved Queen Chrysalis's.