Borusa (True Lords' timeline)

In an alternative timeline, Borusa was the leader of the True Lords. She held the title of Magistrix of the True Lords of Gallifrey, a title that Leela thought was equivalent to Imperiatrix.

Borusa was curious about Leela, Narvin and Romana, and wanted to check that they weren't vampires. She led one final attack on the vampires before she died, not long before Romana opened the transduction barrier. (AUDIO: Annihilation)