Board Thread:The Panopticon/@comment-4028641-20151008023030/@comment-33695797-20191106192741

Regarding the original topic, I was always under the impression that it was the following: Delgado is most likely not the thirteenth Master, since Legacy of the Daleks isn’t explicit, and Doorway to Hell shows Delgado regenerating. Either way, the Master reaches his thirteenth incarnation, and through some event (the Macqueen Master fries him, correct?) becomes decayed. (This Master is played by both Beevers and Pratt, interchangeably. Simply because they are different actors does not mean they are different incarnations.) Eventually he takes over the body of Tremas, and hops between bodies. What happens is unclear, but he is given a new set of regenerations starting with Macqueen.

There is also a quote by Missy in the short story Girl Power! (which admittedly in universe may not be 100% reliable as it's Missy’s account, but may show authorial intent): "Born, Died, Died, Died, Died, Died, Died, Died, Died, Died, Died, Died, Died, Died, Took over some bloke's body, Died, Died, Died, Became a human, Stopped being a human, Died, Died, Became a woman, Ruled!"

- Missy

I’m not sure if “took over some bloke's body" refers to Tremas or Bruce, but I take this as:

Hughes/Dreyfus > several other incarnations (maybe those speculated, such as the War Chief) > Delgado > possibly others > Pratt/Beevers > Ainley, Roberts, and other bodies > Macqueen > Titan > Jacobi (Time Lord > Human > Time Lord) > Simm > Gomez.