Tavosian Union

The Tavosian Union were a force originating on Tavos. They held the Sun-Stealer, and would die trying to protect it. Missy had no problems committing genocide and was prepared to head to Tavos to steal the Sun-Stealer to power her TARDIS before the Time Lords themselves send them to the Kyme Institute to deal with a creature there which would become the power source of her TARDIS. (PROSE: Lords and Masters)