Compilation of three stories that happen behind the scenes of these episodes: Mare in the Moon, MLP The Movie (2017) and the 8th/9th season.

The Comforts of Darkness

Cast: Princess Luna/Nightmare Moon (protagonist) and Princess Celestia.
Timeline: Before and after Friendship is Magic.
Genres: Slice of Life, drama and sad.
Locations: Castle of the Two Sisters (Everfree Forest), Ponyville and Canterlot.
Chapters: 5
Status: Complete.

Does Disney dream of Evil Queens?

Cast: Queen Novo (protagonist, narrator), Princess Celestia, Princess Luna and Princess Cadance.
Timeline: Before and after the movie (2017).
Genres: Slice of Life, first person narrative, drama and sad.
Locations: Canterlot, Seaquestria and Mt. Aris.
Chapters: 3
Status: Complete.

The Mirror of Fire

Cast: Princess Celestia/Daybreaker (protagonist, narrator), Princess Luna, Grandpa Gruff and Garble.
Timeline: 8th/9th season.
Genres: Slice of Life, first person narrative, drama (partially: suicide).
Locations: Canterlot and the Dragonlands.
Chapters: 7 (Part 1)
Status: Incomplete.