Brian the Ood as that is his full name, it wouldn't be like referring to Davros as Davros the Kaled, it's more akin to the Face of Boe being named the Face of Boe, as opposed to just Boe.
Talk about it here.
Brian was an Ood assassin and an ally of the Tenth Doctor during his exploits in the Dark Times.
Biography
Early life
Before the time where his hindbrain would typically be removed, Brian was bought by the Lesser Order of Oberon. They then cut his hindbrain themselves in a dark basement, quickly and roughly, which made Brian obedient, but not docile. (AUDIO: The Minds of Magnox) However, he developed a split personality as his delusions imbued his translation sphere with all the malevolent aspects of his psyche under the name of "Mr Ball". (PROSE: The Knight, The Fool and The Dead; AUDIO: He Kills Me, He Kills Me Not) Brian was torturously trained by the Order. Afterwards, he killed the entire guild. (AUDIO: The Minds of Magnox)
Although Brian did not lose the inbuilt Ood instinct to be helpful and obey human commands, he became, in addition to this persona, a "ruthless" murderer. (PROSE: The Guide to the Dark Times)
Encounter with the Eighth Doctor
Brian was contracted to retrieve Felicity and kill her wife Sophie, by Felicity's father. He pursued the couple to Atharna, shooting down their ship in the desert. Wounded from the crash, Felicity shot Brian whilst Sophie fled, leaving him and Felicity stuck in the desert. The Eighth Doctor arrived and agreed to help them reach the nearest town, Moslin, after they lied that they'd been victims of a bandit attack. (AUDIO: He Kills Me, He Kills Me Not) During their journey to Moslin, the trio rested in a cave. Whilst Felicity slept, the Doctor told Brian a story about a tailor's daughter and how she tried to cheat Death. (PROSE: The Knight, The Fool and The Dead)
In Moslin, the Doctor arranged the town's doctor to treat Brian and Felicity, where they kept the pretense of being together. The Doctor encountered Sophie, seeking shelter with the sheriff in the tavern, and learnt the truth. He devised a situation to trick Brian, managing to rescue Felicity. He reached an agreement with Brian to take him off-world in return for him abandoning his contract. However, as they were boarding his TARDIS, it was captured by the Daleks, with Brian being flung into the Time Vortex. (AUDIO: He Kills Me, He Kills Me Not) The Tenth Doctor's TARDIS spotted him and gave him "a little nudge", believing he could be useful to the Doctor. (PROSE: What the TARDIS thought of "Time Lord Victorious") Brian ended up in the Dark Times. (PROSE: The Knight, The Fool and The Dead)
Association with the Tenth Doctor
In the Dark Times, Brian was hired by High Ambassador Verv-Hoondai Chalskal to test the efficacy of Professor Hana Fallomax's lifeshroud technology. He travelled to Andalia, where he encountered the Tenth Doctor, who did not recall the encounter they had shared in his eighth incarnation and tried to stop Brian attacking Estinee to test the lifeshroud she was wearing. After witnessing Estinee being kidnapped by the Kotturuh during their judgement of Andalia, Brian formed an alliance with the Doctor to find her. Together they travelled to the Kotturuh's planet, Mordeela, where they were attacked by revenants and witnessed Estinee being rescued by Fallomax. As the Doctor worked on the lifeshrouds, Brian discovered Chalskal wasn't the official he presented himself as and was actually sponsoring the project to use as armour for his mercenary forces. Once the Doctor decided that the lifeshrouds couldn't be made to work for longer than a couple of hours and focused instead on reverse engineering the Kotturuh's power, Brian took control of Chalskal's mercenary fleet, believing the Doctor was effectively going to war with the Kotturuh. He made the Doctor the fleet's admiral, to his discomfort.
Brian greeted the Doctor when he returned to the fleet after sentencing the Kotturuh to a lifespan of fifteen minutes on Andalia. The Doctor ordered the fleet to attack Mordeela to seal the Kotturuh's power source, with Brian by his side on the command deck. Brian witnessed the arrival of the Doctor's eighth and ninth incarnations over Mordeela aboard a Dalek saucer and coffin ship, respectively, and their pleas with their future self to stop. (PROSE: The Knight, The Fool and The Dead) During the ensuing Battle of Mordeela, Brian deployed a variety of ancient weapons that he'd collected in the Dark Times, including Uxaerian doomsday particles and a Dæmon heatshield, but was unsuccessful at defending the fleet from the Dalek onslaught and Vampire infiltration. With their ship's engines crippled, Brian attempted to convince the Doctor to use the weapon he'd wiped out the Kotturuh with, but the Doctor refused and instead managed to devise a way for their ship to escape. Brian approved, noting he didn't remain on the scene after performing a kill, and claimed the Doctor was an excellent killer. (PROSE: All Flesh is Grass)
Brian followed the Doctor to a desert planet, where he saved the Doctor from the parasitic ghosts of a long dead ancient species. He admitted that he thought of the Doctor as the closest person he had to a friend. (COMIC: Tales of the Dark Times)
After sometime on the run together, the Doctor heard about Magnox, a centre of knowledge and had them travel there so he could ask a question, which he refused to tell Brian. On Magnox, the Doctor set off for the Chronicon whilst Brian went to explore alone. He saved Wim from being attacked and was recruited into his plot. After an interview with Beck, he was accepted onto their team and told their mission was to assassinate the Council of Minds. The team infiltrated the Chronicon, falling victim to automated traps, but Brian and Wim reached the chamber, arriving just as the Doctor was asking the Minds his question. Brian moved to kill them, but the Doctor held him back and a Kotturuh ship then arrived, demanding the Minds tell them how to defeat the Doctor or they would destroy the planet. Before the Kotturuh came for their answer, Brian killed the Minds. He and the Doctor returned to their ship, accompanied by Wim and Peschell, and fled Magnox before the Kotturuh ship wiped the planet out. They took the Magnoxians to Islos, where the Doctor suggested Peschell join them to Brian's annoyance, though she angrily refused. (AUDIO: The Minds of Magnox)
Brian convinced the Doctor to acquire new weapons for their ship, which he had named the HMS Donna, from the Death Brokers on Entranxis before confronting his past incarnations. The Brokers showed them a Vampire they had captured, Ikalla, and their meeting was interrupted by the arrival of the Eighth and Ninth Doctors. The Doctors rescued Ikalla, but the Daleks attacked, also seeking the Vampire, forcing Brian and the Eighth and Tenth Doctors to return to the Donna. They witnessed the Daleks destroying a coming Kotturuh vessel and wiping out Entranxis by setting its atmosphere alight, which made the Doctors decide to deal with the Daleks they had unwittingly unleashed. Brian accompanied them on their investigation of a damaged coffin ship and subsequent infiltration of the Dalek saucer via a Bloodsman. He stuck with the Eighth Doctor, who talked their way onto the bridge by claiming he was still allied with the Daleks, where they learnt of the Ultimate End from the Time Commander. During a sudden power drain, Brian became separated from the Eighth Doctor, who escaped with the Tenth Doctor, and hid himself on the ship. He intended to understand the Daleks' plan, so he could align himself with the most likely winner. After the Daleks discovered him, he retreated to the engine room and wired himself to an explosive, which would trigger if he was killed. This led to a standoff, during which Brian discovered the co-ordinates of the Daleks' destination and contacted the Doctors on Birinji, who recognised them as that of Gallifrey. The Tenth Doctor rescued Brian using his TARDIS and he joined their effort to defend Gallifrey aboard the Donna. He found that most of his ancient weapons had been spent, but was able to deploy a Kastrian barrier. After the Dalek assault was thrown into chaos by Inyit's judgement, Brian gave the Eighth Doctor a remote trigger for the explosive he had left in the saucer engine room, which the Eighth Doctor used it to force the Dalek ship into the Time Vortex. Brian travelled with the Ninth and Tenth Doctors to Birinji. The Free Undead began settling on Birinj and Brian decided to stay there, parting company with the Tenth Doctor as he left the Dark Times. (PROSE: All Flesh is Grass)
Legacy
River Song included a brief article about Brian in The Dark Times Times, noting that she found him "interesting". (PROSE: The Guide to the Dark Times)
The bowtie of Brian's tuxedo fell through the Time Fracture and became an exhibit at the Verbier Museum of the Impossible. On the day the Faction Paradox masks of Different and Same arrived at the museum, the bowtie rustled with paradox energy. (PROSE: Canaries)
Personality
Brian had "something of a split personality" as River Song described it. Brian had the natural instinct of the Ood and could be very helpful. However, he could also be a "ruthless killer". (PROSE: The Guide to the Dark Times)
Appearance
Brian was an Ood with a translation sphere and wore a tuxedo. (PROSE: The Guide to the Dark Times, The Knight, The Fool and The Dead)