User:MrThermomanPreacher/Sandbox/The Master's fourth incarnation

The death of the Master's fourth incarnation was acknowledged by, herself a product of , on her Spacebook profile. (PROSE: Girl Power!)

The Fourth Doctor speculated that, who made himself known as "the Inventor" on Destination, was in his second or third regeneration. (AUDIO: Blood of the Time Lords, AUDIO: The Destination Wars)

Nature
By their nature as a Time Lord, the Master was born with an initial life cycle of 13 lives, which the Eighth Doctor knew had all been used by the time of 's trial on Skaro. (TV: Doctor Who) Missy acknowledged that she had first died thirteen times before before taking over "some bloke's body". (PROSE: Girl Power!) In fact,, who claimed to be nearing the end of his "twelfth regeneration", had acquired "" in the Trakenite Tremas. (TV: The Keeper of Traken) Surviving his execution on Skaro as a Deathworm Morphant, took the body of Bruce, a human. (TV: Doctor Who)

claimed to Chang Lee that the Doctor had taken most of his regenerations whilst the Doctor told Grace Holloway that the Master was both "on his last life" and had "[ran] out of all his lives". In their ensuing confrontation, the Master claimed that it was because of the Doctor that he had "wasted all [his] lives". The Doctor challenged this, reminding Lee that the Master claimed that he had stolen those lives when the reality was that the Master sought the Doctor's remaining lives after having "used all his lives", noting that the Master himself had just admitted to wasting "all of them". (TV: Doctor Who) In any case, the bodily theft was followed by the Master's fourteenth death. (PROSE: Girl Power!)

Invalid sources
The Doctor Who Role Playing Game by FASA, which admits to taking liberties with the source material in its opening pages, gives a rundown of the Master's first thirteen incarnations in "The Master" supplement book, which was similar to (but not entirely consistent with) the in-universe biography given for the Master in FASA's own CIA File Extracts.

According to the book, the Master could control the form of his incarnations, and frequently used the same face. His first to fourth incarnations lived on Gallifrey, working as a scientist and temporal researcher which entailed a great deal of field work in which he encountered more than his fair share of accidents and dangers, forcing him into regeneration far more frequently than most Time Lords.

This constant form was described as a handsome, apparently middle-aged man distinguished by his tall and slim build with square-cut features, greying hair, piercing grey eyes, his aristocratic bearing and aloof manner. The Fifth Master kept the same face as his predecessors, but lasted over four-hundred-years due to his retirement, showing signs of age as the years went by. He eventually regenerated, aged over 700-years-old, when his rebellion on Gallifrey failed and forced him to become a renegade, with the War Chief among his followers. His next two incarnations appeared as a clean-shaven Monk, whilst the next six returned to a bearded appearance.