Doctor Who: Every Companion Ranked Worst To Best

Another companion that only had a short tenure on the show, Bill found the Doctor working out of a university, where he offers her private tutelage (i.e taking her on adventures across time and space battling Daleks, Cybermen, Ice Warriors, Emoji-Robots, the usual). For Bill, this opportunity was practically a dream come true.

Unlike some of the other companions, Bill was not afraid to argue with the Doctor, showing her temper and chastising him whenever he was being rash, difficult or insensitive. This sets Bill apart from her peers, as she was shown to be more of an independent and unconstrained individual in her own right, and not necessarily wary of contradicting or offending the Doctor if it meant that he would be able to do the right thing. Bill's inclusion in Series 10 provided many firsts for a single character, leading to the creation of an appreciated and respected companion.

It was a shame, then, when Bill's time aboard the TARDIS was cut short by a panicking alien soldier who shot her when she admitted to being human, severely wounding her and rendering Bill in need of serious medical attention. This "attention" came in the form of a cyber-conversion, transforming her into a Mondasian Cyberman. Although she was saved and lived happily, she departed too soon.

In the end, Bill was left with Heather as a sentient water-person to travel the galaxy together. That's nice.