This is a 2-in-1 featuring Twilight and Sunset. The first six chapters are about Twilight's life while the remaining feature Sunset. The pair of interludes provide secondary information about events in the story.
Characters include:
Twilight Sparkle
Princess Luna
Sunset Shimmer
Mane-Six
Humane Seven (NO Sci-Twi)
Vinyl Scratch (both Equestria Girls & original)
Bat ponies (Thestrals)
Star Swirl the Bearded
There are references to the Batman Vampire comics and the Cirque du Freak book series by Darren Shan.
Credit goes to Vector-Brony