5. The Rani
I will kick and scream if we never see the Time Lords or Gallifrey in the show again, even though were pretty much guaranteed to see them again one day. The Master came back twice, so why shouldnt they? But if not the Time Lords, Id definitely settle for the Rani, originally played by Kate OMara during the run of the Sixth Doctor. Basically a female counterpart to the Master, the Rani was a fellow ex-classmate of the Doctor, a scientist who enjoys experimenting on people and other species, if the Master and the Doctor would just stay out of her damn way. Her mindset is not the usual one we see in Doctor Who shes not evil for kicks or for power, but a consequence of her research. Everything comes second to her search for knowledge, even morality. At one point she even teams up with Anthony Ainleys Master (under duress) and at another has the good sense to kick him in the crotch. The Ranis a likely candidate for a comeback, as an exile from Gallifrey its easy to justify her not having taken part in the Time War. Shes fiery, evil and a lot of fun a good campy changeup from the increasingly dark villains of the new series. Who knows if wed see her played by Kate OMara again (whose face has barely changed since the 1980s) or, in the grand tradition of Moffat, a new sassy, sexier regeneration, but the possibilities are infinite..