The sirens use their remaining magic to get revenge on the Rainbooms. They use it on human Twilight and she turns into Midnight Sparkle again. But she isn't evil per say, just studious and a little mad with power.

Twilight lost her horn, when she was a filly. Yet despite all odds, the Element of Magic still claims her as its bearer. Celestia might have made a mistake all those years ago.

The girls meet Fluttershy's twin sister.

Years ago, a human found himself in Equestria, met Chrysalis and had a child. Circumstances forced the man and his child to go back to earth. But now Chrysalis wants to meet her daughter and messes up the teleportation spell.

They thought I was gone, but they should know that the elements don't kill. They gave me a real chance in life and a family. Life was good. Until Celly and Lulu tried out a new teleportation spell.

Twilight's closest friends go back in time and relive their lives. Co-author CrossRedstone

Minako sacrificed her life for humanity. The past millenniums she has been the Great Seal, sleeping a dreaming-less sleep. One day she wakes up in Equestria as a pony, just before the 1000th Summer Sun Celebration.

My sister disappeared ten years ago without a trace. Maybe she is here in this messed up world.