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

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

A Decaying Master
According to Missy and the Thirteenth Doctor, the Master ended up in his rotting, lich-like state when he attempted to regenerate "one time too many" past the twelve-regeneration limit. (PROSE: Meet Missy!, The Doctor vs the Master) Though the Fourth Doctor thwarted the Master's attempt to use the Eye of Harmony to completely regenerate himself, which would have destroyed Gallifrey, (TV: The Deadly Assassin) the Master was able to partially heal himself, (AUDIO: Trail of the White Worm) and eventually came to of the Trakenite Tremas. (TV: The Keeper of Traken)

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.

The Master assumed what was identified as his fourteenth incarnation when his possessed the body of Tremas. This new form was not unlike his but appeared younger with dark brown hair. An attractive man who appeared middle-aged when in reality he was over 900 years old, the Master had an average height and build and was distinguished by his satanic beard and grey eyes whilst wearing a black tunic and gloves. As this body was not Gallifreyan, the Master lacked the natural ability to regenerate, however, exposure to the Numismaton Gas of the planet Sarn gave the Master considerable powers which included the ability to re-trigger a life cycle of regenerations in his stolen body. Escaping his fiery death, the Master regenerated into a fifteenth incarnation with a form identical to that of his previous incarnation.