The Master is a recurring character in the British science fiction television series Doctor Who and its associated spin-off works. The character is a renegade alien Time Lord and the archenemy of the title character the Doctor. The Master has been played by multiple actors since the character's introduction in 1971.
Intelligence and attitude
The Master, played by Roger Delgado, makes his first appearance in Terror of the Autons (1971), where he allies with the Nestene Consciousness to help them invade Earth. The Third Doctor (Jon Pertwee) convinces the Master to stop this plan at the last minute, and the Master subsequently escapes, albeit with his TARDIS, a space-time ship, left non-functioning after the Doctor confiscates the ship's dematerialisation circuit.  Having become a main character in the show's eighth season, the Master reappears in The Mind of Evil, where he regains his TARDIS' circuit from the Doctor after attempting to launch a nerve gas missile that would initiate World War III. After another incursion on Earth in The Claws of Axos, and failing to hold the galaxy to ransom using a doomsday weapon on the planet Uxarieus in the year 2472 in Colony in Space, in The Daemons the Master is finally captured on Earth by the organisation UNIT after Jo Grant (Katy Manning) prevents the alien Azal (Stephen Thorne) from gifting the Master his powers.  In The Sea Devils (1972), the Master is shown to be imprisoned on an island prison off the coast of England. He convinces the governor of the prison, Colonel Trenchard (Clive Morton), to help him steal electronics from HMS Seaspite, the nearby naval base, which helps the Master contact the reptilian Sea Devils, the former rulers of Earth, so he can help them retake the planet from humanity. The Master convinces the Doctor to help him build machinery that would bring the Sea Devils out of their millions of years of hibernation, but the Doctor sabotages the device by overloading it, destroying the Sea Devil base and preventing war between humanity and reptiles. The Master subsequently escapes in a hovercraft. The Doctor reveals in this serial that the Master was once a "very good friend" of his.  Delgado's last appearance as the Master is in Frontier in Space (1973), where he works alongside the Dalek and Ogron races to provoke a war between the Human and Draconian Empires. The scheme fails, and the Master escapes after he shoots at the Doctor.  Delgado was slated to return in a serial called The Final Game, which would have been the season 11 finale. However, he died in a car crash in June 1973 and the story was never filmed.  The Master appeared as a main character of the 1996 Doctor Who television movie, played by American actor Eric Roberts.  In the prologue, the Master (portrayed briefly by Gordon Tipple) is executed by the Daleks as a punishment for his "evil crimes". But before his apparent death, the Master requests his remains to be brought back to Gallifrey by the Seventh Doctor. However, as posited in the novelisation of the television movie by Gary Russell, the Master's self-alterations to extend his lifespan allow him to survive his execution by transferring his mind into a snake-like entity called a "morphant". This interpretation is made explicit in the first of the Eighth Doctor Adventures novels, The Eight Doctors by Terrance Dicks, and also used in the Doctor Who Magazine comic strip story The Fallen, which states that the morphant was a shape-shifting animal native to Skaro.  Using his morphant body to break free from the container holding his remains, the Master sabotages the TARDIS console to force the vessel to crash land in San Francisco at the start of Earth's new millennium. From there, the Master has the morphant enter the body of a paramedic named Bruce to take control of him. However, the Master finds his human host to be unsustainable as the body slowly begins to degenerate, although the Master has the added abilities to spit an acid-like bile, both as a weapon and to mentally control victims as an alternative to his usual hypnotic abilities. The Master attempts to access the Eye of Harmony to steal the remaining regenerations of the Eighth Doctor (Paul McGann), but instead is sucked into it and supposedly killed.  The Master and the Doctor are shown to have similar levels of intelligence, and were classmates at the Time Lord Academy on Gallifrey, where the Master outperformed the Doctor. A similar connection between the two was also referenced in The End of Time in which the Master reminisces with the Tenth Doctor about his father's estates on Gallifrey and his childhood with the Doctor before saying "look at us now". In the 2007 episode "Utopia", the Tenth Doctor calls the transformed and disguised Master a genius and shows admiration for his intellect before discovering his true identity. The Tenth Doctor further expresses admiration for the Master's intellect in The End of Time by calling him "stone cold brilliant" and yet states that the Master could be more if he would just give up his desire for domination. The Twelfth Doctor states that Missy is "the one person almost as smart as me" ("The Lie of the Land").  Delgado's portrayal of the Master was that of a suave and charming sociopathic individual, able to be polite and murderous at almost the same time. His design is homage to the classic Svengali character: a black Nehru outfit with a beard and moustache.  Aspects of Simm's portrayal of the Master parallel Tennant's Doctor, primarily in his ability to make light of tense situations and his rather quirky and hyperactive personality. According to the producers, this was done to make the Master more threatening to the Doctor by having him take one of his opponent's greatest strengths, as well as making the parallels between the two characters more distinctive. This rationale is written into dialogue by the Master in "Utopia", in which he explicitly states, as he is regenerating, that if the Doctor can be young and strong, then so can he. In an episode of Doctor Who Confidential, "Lords and Masters", Russell T Davies also classifies the Master as both a sociopath and a psychopath.  Michelle Gomez maintained Simm's portrayal of the character, specifically the psychopathic behavior and inappropriate emotional responses to certain situations, as well as the original traditions of ruthless, murderous behaviour and grandiose, Machiavellian criminal intelligence that have been consistent throughout all incarnations. However, she also displayed a much more coquettish manner, with her new female identity allowing her to fully express aspects of the Master's ambiguous bond with the Doctor (as previously explored by Simm's incarnation in "The Sound of Drums"). While determined to torment and corrupt the Doctor with moral temptation while inflicting pain and death to humanity, she frequently referred to him as her "boyfriend" or "friend" and appeared to ultimately desire his acquiescence and company. She is also well aware that she is even more dangerously psychopathic than before, describing herself as "Bananas" to UNIT agent Osgood right before killing her ("Death in Heaven"). However, when circumstances result in Missy being kept in a vault and monitored by the Doctor after an averted execution, Missy actually comes to show signs of remorse for what she had done in the past, to the point that she prepares to side with the Doctor over her own past self ("The Doctor Falls").

Q: Is he a very intelligent person?
A: The Tenth Doctor further expresses admiration for the Master's intellect in The End of Time by calling him "stone cold brilliant

Q: What makes him brilliant?
A: Delgado's portrayal of the Master was that of a suave and charming sociopathic individual, able to be polite and murderous at almost the same time.
Was he liked by others?
The Doctor reveals in this serial that the Master was once a "very good friend" of his.
The Doctor reveals in this serial that the Master was once a "very good friend" of his.