Doom

Doom was the self-proclaimed "universe's greatest assassin", a member of the Lesser Order of Oberon. She owned a vortex manipulator.

Early life
Doom claimed to have been given the name by her mother, instead of choosing it as some kind of assassin nom de guerre. (WC: Meet Doom - the Universe's Greatest Assassin!) She once told River Song that she hadn't been born a killer, but that life had made her that way - claiming that although she didn't enjoy killing, she had to do it if she wanted to continue being herself. (COMIC: Target Selected)

Doom eventually joined the Lesser Order of Oberon. She considered herself to be a very good assassin, claiming to be the best on the Lesser Order's books, although Order office worker Terri did not regard her as important. Her victories included overthrowing the Daedalus Conspiracy, sealing the Mandeville Dimension, and saving Princess Agatha from her seven deadly husbands, having had only one shot at each. (PROSE: Hour One)

Unleashing Death
Having been assigned to kill a target at Duke Derek Gamma's Masked Ball on New Venice, Doom encountered the Doctor, who warned her that she was about to make a terrible mistake. Ignoring him, she killed her target with her staser rifle, and "everything went wrong" - causing Death to be unleashed upon her, which ensured her demise in only twenty-four hours, according to the life-signs reading on her vortex manipulator. Calling Terri at the Lesser Order of Oberon's headquarters, she asked for and obtained a new list of targets, hoping to run into the Doctor along the way so as to ask them how to save her life. Her first selection was a target in the Stormcage Containment Facility, as she knew that inmate River Song had a connection with the Doctor. (PROSE: Hour One)

As she started running, she sent out a video S.O.S. from a deserted planet, explaining her situation and asking anyone with the means to do so who received the message to contact the Doctor on her behalf. (WC: Meet Doom - the Universe's Greatest Assassin!) Contemplating the holographic timer display on her vortex manipulator, she reflected that she now had only 24 hours to find the Doctor. (WC: The universe's greatest assassin has just 24 hours to escape Death and find the Doctor - where will Doom's Day take her next?)

Searching for the Doctor
After dispatching her target at Stormcage, she sought out River Song, who empathised with her outlook on life and told her where she could find the Doctor - the Waxworks Museum on New Calamino. Thanking her, Doom selected a target at the museum and departed as the second hour of her day ended and Death began to close in once more. (COMIC: Target Selected) Arriving in the museum, she set to work searching for both her target - one Minister Scarling - and the Doctor. She encountered the latter in his sixth incarnation, disguised as a wax model. Working together, the two of them fended off a Nestene attack on the planet, melting Autons with molten plastic before destroying their source by pushing the corrupt minister into it, dispatching him. Doom made her plea to the Doctor, but he revealed that he was not the incarnation with the ability to help her, and that she would need to keep searching. The hour up, Doom set off for another target. (COMIC: The Plastic Population)

In a 1930s Hollywood film studio, Doom found no trace of the Doctor, instead discovering that every actor in the studio had been cyber-converted. Having run out of molten plastic, she fled the Cybermen, and sought her target - actress Polly Church - in hopes of quickly ending the mission. Finding that Polly, too, was now a Cyberman, Doom realised that her father had ordered her killing as a mercy, and obliged, detonating a crate of pyrotechnics in the prop room to destroy the Cybermen before departing. (COMIC: High Noon in Hollywood)

Arriving at a renaissance marketplace, Doom expressed dismay at the difficulty of her next target, finding that she had been tasked with killing the idea of the unicorn to prevent them being hunted to extinction. Setting off, she quickly located a market stall selling unicorn hair and horns, and offered a chest of prop gold in exchange for the entire unicorn, claiming to be a great hunter with a desire to add a unicorn to her list of kills. Jo Grant, independently in the process of trying to save the unicorns in the course of her travels with the Third Doctor, attempted to stop her, but she assured Jo that she was working towards the same goal. As the unicorn was presented to her by the stall's huntsman, she used one of her devices to disguise it as an ordinary horse with a fake horn, ending the people's belief in real unicorns. Having put a tracker on the huntsman, Doom said goodbye to Jo, setting off as Death closed in on her again. (COMIC: The Horn of a Dilemma)

Looking at the timer display on her vortex manipulator, Doom noted that, with 19 hours left, she had already faced Autons and Cybermen and met a few Doctors - but still had yet to locate the right one. (WC: Mission update from Doom!)

Doom's next target was at a masked ball in 19th-century New York. Investigating, she encountered Lord and Lady Prettypaw - whom she recognised as notorious thieves, and who were engaged in the process of breaking into a jewellery safe. Deducing that they had come for the Perpetual Topaz, a weapon of mass destruction which had been concealed on the primitive Earth, Doom utilised her mask as a throwing weapon to kill the Lord, before eliminating his sister with her staser rifle. Before leaving, she briefly encountered Missy, also in attendance at the party and attempting to play the role of "Doctor Who". Despite her claims, Doom immediately recognised that she was not the Doctor and told her as much, before departing for her next target - once again, located in the Stormcage Containment Facility.

Meeting with administrator Cire, Doom informed him that Stormcage was in danger thanks to her next target - an unknown party who had infiltrated the prison's staff with plans to hire out its worst prisoners to interested parties. She set off to find the person in question, only to find that Missy - irked by her remarks, and looking for the topaz - had followed her, intending to prove that she was in fact the Doctor. Doom, still failing to buy into her act, asked for identification, which Missy could not provide - causing Cire to grow suspicious of her as well and prompting him to call security. With the guards distracted, Doom began to search for her target, still trailed by Missy, and hacked into the cell of a prisoner, lowering the bars. Although this was not her target, her arrival caused the prisoner to inadvertently reveal the target's name. Doom thanked the prisoner, then proceeded to cut him in half with the re-activated cell bars, noting that he too was on her list. Encountering the correct target, unpaid intern Jaxxo, she killed him with her staser. She ran into Missy again, and refused to tell her what she had done with the topaz before departing for her next location. (COMIC: A Doctor in the House? Part One)

At the 34th Annual Old Earth Convention at the Canis Major Overdensity Convention Center and Resort, at which she hoped the Doctor might be in attendance, Doom noted her love for convention shopping, planning to buy some rebar despite her strict schedule. Having done so, she soon encountered Missy for a third time. Initially mocking Missy's desire to prove herself as the Doctor, she eventually proposed a partnership - reasoning that, if Missy really was the Doctor, she should have no problem navigating a convention dedicated to their favorite planet. The two worked together to dispatch Doom's next target- an extremist with the Church of Omitted Yesteryear who sought to destroy all books originating from the old Earth - a feat which involved Missy knocking her out with an anatomical encyclopedia before Doom strangled her with string. Still refusing to reveal the location of the topaz, Doom went in search of her next mission.

On a dying world, Doom was tasked with killing a man who, as the last living member of his species, intended to kickstart a universal genocide using the topaz to ensure that his people would be remembered. Sharing tea with the man, Doom covertly poisoned his beverage - then, feeling that Missy's desire to convince her that she was the Doctor had begun to interfere with her mission, waited for the Time Lady to arrive before posing her a challenge - finding a way to avert the genocide and save the memory of the man's species in a non-violent manner, thereby proving herself to be the Doctor. Unable to do so, Missy gave up, just as the man died of the poison which Doom had given him. Although Missy claimed that she was, if not the Doctor, still a better upgrade, Doom told her that she needed the actual Doctor - then informed Missy that she hadn't poisoned her tea, as Missy was not yet a target. Having already incinerated the topaz and the man's weapons and replaced them with a hologram generated by one of her devices, Doom left the planet. (COMIC: A Doctor in the House? Part Two)

Noting that she now had 15 hours left to find the Doctor, Doom expressed confusion when the timer display on her vortex manipulator was suddenly replaced with a holographic image of a robot dog. (WC: 15 hours left to find the Doctor, and Doom receives an unexpected communication - from a very good boy!) Responding to K9's distress call asking for someone to nonviolently dispatch the Scarlet Scavengers attacking the robotic haven of Cal-Q-LOn for scrap parts, she agreed to assist in exchange for information about the Doctor. Doom dispatched the pirates, then arrived at the space station and introduced herself to K9 and the Thirteenth Doctor - but became suspicious of the latter after a few slips of the tongue suggested that she was a robot. Accusing them of this, she found that she had been correct when the "Doctor" revealed themself to in fact be Kamelion disguised as the Thirteenth Doctor, having taken that form to help fend off the pirates - although she was surprised to find that he was a shapeshifter, as she had expected a straightforward android duplicate. After a brief conversation about Kamelion's past, the pirates attacked again, but Doom revealed that she had arranged for a freighter of faulty parts, painted red, to be delivered to the Scarlet Scavengers - causing their ships to fail and forcing them to halt their attack. K9 promised to inform the Doctor of Doom's quest the next time they met, and Doom returned to the Time Vortex in search of another mission. She lamented her lack of success thus far, worrying that she would run out of time and suffer the consequences if she didn't find the Doctor soon, before her vortex manipulator located another target and prepared to make the jump. (GAME: AI am the Doctor)

Behind the scenes
To be added