Fan Casting Doctor Who: Post-1989 The Rani

This would ultimately end after she was converted into a Cyberman, initiating self-destruct in anger at the fact that the Doctor had left her for dead, regenerating as a result, and according to her, gaining a full new set of regenerations as a result, on top of those she already possessed, a claim the Doctor found dubious. Her third incarnation wreaked her vengeance on both the Doctor and the Cybermen, blaming the two of them for her experience, quite rightly. She became far more sadistic, and attempted to kill the Doctor so his body could be used in her experiments multiple times.