Krasko
Krasko was a murderer from the 51st Century who was sent to, then released from the Stormcage Containment Facility. He murdered around 2000 people. Whenever he remembered what he'd done, he was delighted with the memory, though Stormcage had punished him by installing a neural implant that stopped him from trying to murder anyone, no matter how much he wanted to.
The Thirteenth Doctor, Graham, Ryan, and Yaz encountered him in Alabama 1955, after finding a suitcase of time displacement equipment. He wanted to change history by making Rosa Parks not go into the bus.
Krasko knew about TARDISes, as he recognised the Doctor's TARDIS as one. (TV: Rosa)
Biography
Krasko was originally imprisonned in the Stormcage prison planet for murdering over two thousand people. During his stay he decided to alter the course of history in order to put colored people “back in their place” and concluded that he needed to displace Rosa Parks in order to accomplish this. After carrying out his sentence, Krasko was released and set out to carry out his plan. After acquiring a time displacement gun and a vortex manipulator, Krasko travelled back in time to Alabama in 1955. (TV: Rosa)
