For those who might be interested. I just wrote the teaser for a new Dr. Who fanfic. This idea is based more on the classic series than the current incarnation, but if it goes long enough it'll touch on the latter -
Title
Doctor Who: A Different Body A Different Destiny
Summary
What if rather than Tremas the Master had absorbed the body of Nyssa on Traken? Now biologically female the Master decides to set a different type of trap for the Doctor. Going by the name Samantha "Sam" Ret she tricks the Doctor into becoming one of his companions. However, when romantic feelings start to develop between her and the Fifth Doctor things become complicated.
Characters
Fourth Doctor, Fifth Doctor, Adric, Master, exact
https://www.fanfiction.net/s/13005879/1/
If so inclined, enjoy.