Shanstra
Shanstra was part of a Sensopath trinity. Her other two segments were Jirenal and Kelzen. She had red hair.
After being exiled from the far future, she appeared at the human colony of Gadrell Major. Suzi Palsson found her and fell under her control. Shanstra grew stronger from feeding on Suzi's memories of her dead lover Colm.
When they were attacked by three feral children, Shanstra psychically killed one of them. Another, Trinket, ran away. She let the third, a girl called Livewire, survive. The young girl was consumed with hate for the Phractons that had invaded the colony. This provided much more energy for Shanstra than Suzi, who fled as Shanstra's focus on her diminished. When she met the Phracton Secondary, though, his hate for the humans was even greater. Shanstra abandoned Livewire and made the Secondary her new power source.
Unable to link with Kelzen because the Seventh Doctor had put her in the Zero Room, she focused on Jirenal. The two eventually mentally reunited. However, Shanstra did not want to share consciousness, but be the dominant personality in the triad. When Kelzen realised this, she distracted Shanstra through their mental link. This allowed her to be killed by Livewire, seeking revenge for Shanstra leaving her. Due to the Sensopath's connection, Jirenal and Kelzen died as well. (PROSE: Infinite Requiem)