Estinee

Estinee was the last of the Destrans following the Kotturuh's judgment of her home-world in the Dark Times. She survived due to having an immunity to death and became crucial in the Tenth Doctor's campaign against the Kotturuh.

Biography
The Kotturuh kidnapped Estinee after finding her immune to their touch during their judgement of Destran, in which her entire species died. They kept her on their home planet Mordeela, where she witnessed many delegates attempting to bargain with the Kotturuh.

She was rescued by Professor Hana Fallomax, who was using mining robots to mine crystals from Mordeela to create Lifeshrouds to protect against the Kotturuh. The Lifeshroud actually worked on Estinee, so Fallomax started using her in demonstrations of the Lifeshrouds to sell them on worlds fearing the Kotturuh's coming. Estinee constantly wore her Lifeshroud bodysuit, believing that it was keeping her from death by the Kotturuh's "gift". At one point, she was recaptured by the Kotturuh, but Fallomax was able to rescue her from Mordeela a second time.

Estinee first encountered the Tenth Doctor on Andalia, where she was demonstrating the Lifeshroud. He saved her from Brian the Ood, who had been contracted by Fallomax's sponsor, Ambassador Verv-Hoondai Chalskal, to test the Lifeshroud's efficacy by attempting to kill Estinee. The Kotturuh arrived on Andalia to judge the planet and recaptured Estinee. The Doctor and Brian followed them to Mordeela and watched as Fallomax rescued Estinee again via a mining robot. The Doctor and Brian followed her again to Fallomax and the Doctor agreed to work on the Lifeshrouds, but soon discovered they only worked on Estinee due to her natural immunity. He instead decided to reverse-engineer the Kotturuh's power and took Estinee and Fallomax with him back to Andalia, where he made two solutions; one to give the Kotturuh a lifespan, and the other to simply wipe them out. The Kotturuh used the influence they had over Estinee from her time on Mordeela to have her pilot the TARDIS forward in time to the date they had appointed as the Doctor's death and had her kill Fallomax for good measure. They attempted to force her to shoot the Doctor, but she refused and used the gun to detonate her Lifeshroud, vaporising herself. (PROSE: The Knight, The Fool and The Dead)

Post-mortem
Infuriated by Estinee's death, the Doctor unleashed his virus to wipe out the Kotturuh by giving them a lifespan of fifteen minutes. Unbeknownst to him, Estinee's immortality had extended beyond her physical form. Now incorporeal, Estinee observed the Doctor leaving the planet and wished him all the luck and strength he would need for the coming crisis. (PROSE: The Knight, The Fool and The Dead)

Appearance
Estinee appeared to be around fifteen-years-old, with sharp and thin features and yellow skin. Her eyes were owl-like and her hair was wild green like seagrass. (PROSE: The Knight, The Fool and The Dead)