Azure

Azure was one of the two Ravagers who led the fight against the Time Lords in the Founding Conflict which ended the Dark Times, opposing the Time Lords' intention of using the power of the Mouri to bind time. Defeated at the Siege of Atropos by the Fugitive Doctor, she remained hidden on Earth inside a human guise until she was awakened by her brother Swarm. Like him, she could reduce living things to ash with a touch as well as teleport herself across space and time at will. Swarm noted that "Swarm" and "Azure" were only translations of their actual names, albeit serviceable ones.

Biography
Azure and her brother Swarm discovered the Division's greatest secret - the six Mouri in the Temple of Atropos on the planet Time that controlled time. Viewing this as heresy, the pair took over the Temple and evicted the Mouri, bringing along millions of hostages within Passenger forms. The Division dispatched the Fugitive Doctor to capture them and restore the Mouri. The Doctor confronted Azure and Swarm and revealed she'd had the Mouri hide themselves inside one of the Passengers, unleashing them to retake their positions whilst her team immobilised Azure and Swarm. (TV: Once, Upon Time)

Azure and Swarm were officially banned from the Temple thereafter, with Mouri being quantum-locked against them in fear of their return. (TV: War of the Sontarans)

While her brother was imprisoned by the Division in a containment chamber, Azure had her identity erased (TV: Once, Upon Time) and was trapped within a human form, unaware of her true nature. Now called Anna, she lived in the Arctic Circle with her partner, Jòn. After eons of confinement, Swarm escaped and travelled to the house and, after destroying Jòn, brushed a finger against Anna, causing the human disguise to burn away, revealing Azure.

Now freed and active once more, Azure made her way to Liverpool where she took over a large, gothic house. As Diane was walking past the house, Azure psychically called to her, telling her to get inside the house; when Diane refused, Azure remotely forced her to walk forward against her will, dragging her into the darkened, flooded house where she revealed herself to Diane, telling her that she and her brother were "going to have fun with [her]". (TV: The Halloween Apocalypse)

Swarm, Azure and a Passenger form transported themselves to the Temple of Atropos, where Azure destroyed the first of the two Priest Triangles. The three came across Yasmin Khan and Inston-Vee Vinder, who fruitlessly attempted to shoot first Swarm, then Azure herself, with the two taking childlike glee in teleporting across the room to avoid his blaster-fire. She witnessed Swarm's preparations to turn Yaz and Vinder into temporary Mouri and the arrival of the Thirteenth Doctor, her TARDIS and Dan Lewis to the Temple, with Swarm giving her the responsibility of incanting the countdown to him clicking his fingers and unleashing the "full force of Time" onto the bound Yaz and Vinder. (TV: War of the Sontarans) The Doctor pre-empted him by leaping onto a broken Mouri's position and taking the force of time upon herself to save her friends, managing to work with the surviving Mouri to hide four replacements within Passenger to restore time to normal. Azure and Swarm congratulated her however revealed time had been broken long enough to unleash particles of the Time Force. Triumphant, they departed the Temple. (TV: Once, Upon Time)

Azure visited the survivors of the Flux gathered on Puzano, promising to take them to safety in another galaxy. Claiming Passenger would transport them there, she tricked them into entering its transportation field willingly. (TV: Village of the Angels) Swarm and Azure then used the sacrifice of these prisoners to strengthening Swarm's existing psychic connection with the Thirteenth Doctor into a psycho-temporal bridge to her current location: Division Control. There they found the "Awsok" Tecteun and the Doctor, with Swarm killing Tecteun in revenge for his imprisonment and cornering the Doctor. (TV: Survivors of the Flux) Removing her conversion plate, the Doctor allowed two splinters of herself to return to the universe, but one remained in the outpost, where Azure revealed her and her brother's true purpose to her: to get endless revenge on the physical universe by using Tecteun's Flux to finish destroying it, then, once Time was unbound from Atropos, rewind and replay this moment over and over again for their own amusement.

Secure in the knowledge that the final Flux event was in motion, Azure and Swarm transported themselves and what they believed to be the only Doctor to the planet Time; they intended to sacrifice the Doctor, as "the first Time Lord", to the embodiment of Time, whom they viewed as their saviour. Time appeared to the Ravagers at the outskirts of the temple, appearing as a duplicate of Swarm; aware that the Flux had already failed, and still being bound to Atropos, Time chastised Swarm and Azure for failing to free them, and disintegrated them. Unlike Swarm, who was much distressed at this turn of event, Azure seemed to delight in her final moments, viewing her disintegration by Time as an "ascension". (TV: The Vanquishers)

Appearance and clothing
Like her brother in his renewed incarnation, Azure dressed in intricate, embroidered clothing. She had light blue skin with gold and darker-blue accents, bright blue eyes, and visible sharp teeth. (TV: The Halloween Apocalypse)

Behind the scenes

 * According to Chris Chibnall in WC: The Flux: Story Breakdown, Azure had been placed in a "brutal memory wipe witness protection" after her capture by the Division to keep her separated from Swarm. He also explained that Swarm and Azure's plan was for Time to "erode Space" and become a "maligned force to be unleashed across the whole universe", and that they used the carnage of the Flux to achieve that goal.