Krasko
From Tardis Wiki, the free Doctor Who reference
Krasko was a murderer who was sent to, then released from the Stormcage Containment Facility. He murdered around 2000 people. 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. (TV: Rosa)