Ollistra (The Side of the Angels)

Cardinal Ollistra was a high ranking Time Lord involved in the Time War

Biography
When Padrac revealed the imminent destruction of the universe to the council of the Time Lords, Ollistra, together with some members of the Enclave, fled Gallifrey and hid in New York City, Earth during the 1970s. She met and together, they infiltrated the business industry of the city to create structures  and buildings resembling those of Gallifreyans in order to shield themselves when the destruction of the universe comes. She also formed an alliance with the Weeping Angels to power these structures. To act as her eyes and ears, she also sent Volstrom and Veklin to the Crucible of Souls to spy on Padrac.

When the Eleven came to New York to confront Ollistra and the Eighth Doctor, she was pushed from a building by him, which triggered a regeneration. (AUDIO: The Side of the Angels)

During the Last Great Time War, Ollistra was present when a Gallifreyan reported the destruction of the Dalek fleet and the death of the Doctor. Horrified, Ollistra laments Time Lord soldiers Bennus and Arverton when they allow the War Doctor to activate the Dalek Time Destructor instead of them, a blast no Time Lord can survive. Ollistra attends the Doctor's funeral, skeptical of his demise. With her strong belief that the Doctor was still alive, she sent Veklin to search for him. After gaining control of the Eye of Harmony of the Doctor's TARDIS, Ollistra pulled the Doctor from Keska when he refused to go home. (AUDIO: The Innocent)

She later built a team, consisting of the War Doctor, Veklin, Bennus and Arverton, to rescue Seratrix, a Time Lord strategist, in the "Null Zone". (AUDIO: The Thousand Worlds)

It was later revealed that the scheme underneath the mission was to purge the idea of Seratrix to make peace with the Dalek. The reason why she sent the "rescue team" was because she believed that the Doctor, Bennus, and Arverton were followers of the belief of Seratrix so they should be killed together with him.

After the War Doctor stopped the plan of the Daleks to explode the thousand planets, Ollistra came and revealed her plan to the Doctor. After that, she brought the Doctor to the future of Keska to show how the planet recuperated from the invasion of the Daleks. (AUDIO: The Heart of the Battle)

Ollistra caught up with the Doctor after he used the Annihilator to erase the Technomancers, placing him under arrest as a war criminal. (AUDIO: Legion of the Lost)

She was looking for the Doctor in order for him to understand the whether they should use the anima device. She then decided to take on a mission to Asteroid Theta 12 to discover the secrets that they were the war council was hearing. She was reluctant to save Jarad. She discovered the research that the Daleks were doing. The Doctor got her to use the anima device in order to destroy the Dalek fleet. The Doctor left her behind on the Asteroid. (AUDIO: A Thing of Guile)

Ollistra followed the Doctor to the Neverwhen as his TARDIS was used to travelling to strange places. She was interested in the results of the weapon that created the Neverwhen, especially because it resurrected Time Lords. The Doctor later used it to create a state of peace where both Daleks and Time Lords were farmers. Ollistra planned to use it along with the Neverwhen to destroy Skaro. (AUDIO: The Neverwhen)

Ollistra later got Heleyna to contact the Doctor when the quantum shield around Earth was breached. She was kidnapped soon after this. (AUDIO: The Shadow Vortex)

She went to a retreat to gain information about a Dalek Spy in the High Council, where she was taken by General Fesk to be used as a bargaining chip between the Sontarans and both the Daleks and the Time lords to let them into the war. She discussed the beginnings of the war with the Dalek Time Strategist. She was rescued when Fesk was trapped with the Doctor with their temporal weapon. (AUDIO: The Eternity Cage)

She was then taken prisoner by Heleyna and who was the spy. Ollistra then used the Battle TARDIS' to save the Doctor when he was falling through the Rovidian atmosphere. She fell to the lower levels of the TARDIS, and ended up in the infirmary. Heylena wanted her as she was one of the War Council and had access to the Eye, to punish her for the death of Heleyna's grandfather and prevent the war from ever happening. After the Daleks were stopped she helped the Doctor to set the time rotor to get them out of the time vortex. (AUDIO: Eye of Harmony)

Personality
Ollistra was a heartless politician, so much so that Bennus and Arverton joked over the existence of Ollistra's emotions, and was also deeply patriotic, allowing Gallifreyans to sacrifice themselves for the greater good. She displayed a discontent with the Gallifreyan armed forces, telling two soldiers "The Doctor is worth a hundred of you... people!". (AUDIO: The Innocent)

Relationship with the War Doctor
Although Ollistra respected the Doctor's efforts for Gallifrey, she also appeared to despise him, describing him as "a thorn in [the Time Lords'] side" and "An embarrassment for most of his lives." When he was presumed dead, Ollistra confessed that she felt the universe "a far more dangerous place without [him]", displaying that she had some level of recognition for his pursuits and actions. (AUDIO: The Innocent)