Vassarian's TARDIS
During the Last Great Time War, Vassarian operated a Battle TARDIS.
In the latter half of the war, the TARDIS was shot down by the Daleks, crashing on a moon. With both pilot and ship damaged, Vassarian ejected the ship's Eternity Cage, hoping to hold himself in stasis while the TARDIS repaired itself. As the Eternity Cage sealed around him, Vassarian began to regenerate. Unable to complete his regeneration, Vassarian began leaking artron energy, attracting the attention of the Sontarans. Seeking to join the Time War, the Sontarans used Vassarian as a power source to develop time technology. The TARDIS was moved to Rovidia, its key held by General Fesk.
Aware of what was happening, Vassarian manipulated the Sontarans into abducting the War Ollistra so that the Dalek Fleet would be drawn to Rovidia and destroy the Sontarans. When this also brought a Time Lord rescue party, Vassarian made contact with the War Doctor letting him know what had happened and instructing him to escape in his TARDIS before he died. After the Doctor claimed the key from Fesk, the ship took off only for Heleyna, having been manipulated by the Dalek Time Strategist, to take control of the TARDIS and kick the Doctor out of the ship when it was in Rovidia's atmosphere. (AUDIO: The Eternity Cage)
As Heleyna struggled to establish contact with the Dalek Time Strategist, Ollistra and Kalan managed to trigger the TARDIS's short-range transmat recall, saving the Doctor. Using a time mine, Heleyna managed to escape deeper into the ship with Ollistra as a hostage. Making her way to the star chamber, Heleyna opened a path for the Temporal Assault Squad to reach the Eye of Harmony only for the time winds to destroy the Daleks. Using the architectural reconfiguration system, the Doctor forced the TARDIS to eject the star chamber, depriving it of power. As the ship began to collapse, the Doctor managed to convince a repentant Heleyna to detonate the Daleks' Primary Weapon to give the TARDIS enough power to exit the Time Vortex, the ship crashing back on Rovidia. (AUDIO: Eye of Harmony)
