Gravity is not on the "good side,". She is not part of the rebellion. She does not believe in what they do. Because apparently they believe in destroying her home.

Who is Queen Chrysalis? It started over a thousand years ago, when a young Princess Chrysalis's destiny intertwined with a very dangerous stallion.

Sherlock and John have been transported to Equestria! Living with a crazy mare searching for her dead brother, secrets are revealed, and mysteries are solved

Celestia has transformed into a wicked mare of light, seeking to control Equestria with an iron hoof. Luna needs to use the most powerful artifacts known to pony kind- the Elements of Harmony- to stop her.