Unhappily Ever After by Jeff Hong
rickandmortyheadcanons
Rick and Morty Headcanon #317
Rick was kept as a prisoner by the Galactic Federation, along with Birdperson and Squanchy and their crew, and was experimented on while held captive. He was taken because of how smart he was, and the GF wanted to use him to expand outside the galaxy. The experiments caused him to age slower, and it enhanced his ability. The atrocities mentioned by Birdperson were committed in a guerrilla war against the GF
(submitted by an anonymous user)