Following the events of Survival, the Masterís destiny appears to take two mutually exclusive tracks.
In publishing terms, the first adventure to feature the Master after Survival was First Frontier, in which itís stated that he leapt directly from the Cheeta World to 1950s Earth, where he set his plans involving the Tzun in motion. The Tzun healing nanites granted him a new cycle of regenerations, and he used one of them when Ace shot him, regenerating into a new form which the author has described as being played by Basil Rathbone. However, in his next published appearance in Happy Endings, the Master is once again experimenting to create a new body for himself, and when he appears in the TV-Movie, heís at the end of his cycle of lives once more. Presumably, therefore, the nanites werenít as effective as they seemed at first. The TV-Movie marks his last appearance to date on the Doctorís timeline, although the unnamed man who appears in The Adventuress of Henrietta Street wearing a rosette is undoubtedly intended to be the Master, alive after all. We await future developments.
The stories written by Mike Tucker and Robert Perry, however, plot out a different series of events after Survival (and presumably before First Frontier). In the short story Stop the Pigeon and the novel Prime Time, the Master is still in Tremasí body, and is suffering from the Cheeta infection. This contradicts the claim in First Frontier that he travelled directly from the Cheeta world to Earth. Furthermore, in Dust Breeding the Master reappears as an animated corpse, who claims that his Trakenite body was stripped from him by the power of the Warp Core. This is not entirely without precedent; in The Quantum Archangel, itís suggested that Tremasí body is superimposed, as it were, over the decaying remains of the Masterís Time Lord form, and that only the embers of the Source of Traken -- or afterwards, the Lux Aeterna -- keep it in one piece. However, it is as yet unclear how, or even if, the Master of Dust Breeding and Master gets to be the Master of First Frontier... or vice versa.
What follows is therefore entirely speculative. One theory suggests that the Tzun created a clone of the Master for experimental purposes, and that it got away from them. We leave it up to the reader to decide which of the Masters, in this case, is the original. Another theory is that we are seeing two contradictory timelines for the Master, and that following the Chronovore attack at the end of The Quantum Archangel, one of the timelines is devoured. For those who prefer a tidier explanation, we suggest that in an as-yet unrecorded adventure following Master, the Master finds a way to roll his own personal timeline backwards, restoring himself to his Trakenite body -- unfortunately with the Cheeta infection still present -- and thus setting up the events of First Frontier.