Mathara

Mother Mathara was a member of Faction Paradox. When Fitz Kreiner arrived on one of the Faction's warships after having been sent through the Cold, Mathara initiated him into the Faction. (PROSE: Interference - Book One and Book Two)

One of her protégés from Earth was considered a "very promising young cousin" by Father/Mother Olympia. (PROSE: Newtons Sleep)

Later, Mathara led the Faction warfleet to the planet Dust, accidentally infecting the Third Doctor with a biodata virus during his paradoxical death. She observed the changes in the Doctor's timeline, already knowing the result of what was done would not be seen until the time of the Eighth Doctor. (PROSE: Interference - Book Two)

Nearly three centuries into the War, the Faction had devolved into a militaristic sect of terrorists (PROSE: The Gallifrey Chronicles) long after the Eleven-Day Empire's destruction in the War's fiftieth year. (AUDIO: The Shadow Play) This sect was led by Mathara and her warships. She allied herself with Uncle Kristeva and followed a future version of the Doctor claiming to be Grandfather Paradox, a possible result of the biodata virus launched on Dust. (PROSE: The Ancestor Cell)

Mathara went back to the War's beginning, prior to the Event (PROSE: The Ancestor Cell) or the Cataclysm, (PROSE: Alien Bodies, The Book of the War), following the Grandfather's plan to take over Gallifrey and launch a front against the enemy. (PROSE: The Ancestor Cell, The Gallifrey Chronicles)

Mathara's fleet invaded Romana III's Gallifrey on the eve of the Event while the planet was under the corrupting influence of the Edifice. She, and her fleet, were obliterated when the Eighth Doctor used the Edifice to destroy all of Kasterborous in an attempt to end the War. (PROSE: The Ancestor Cell)