Doctor Who: New Who Companions, Ranked Least-Most Likely To Win Squid Game
The Doctor has surrounded himself with a wide range of different individuals over the years in Doctor Who, and with such diversity comes a broad spectrum of combat and strategic abilities that would help them in a deadly scenario. Whether it's their combat skills or their strategic intelligence, each one of the Doctor's companions has something different that would aid them in Squid Game's televised fight to the death.
Their battle strength and quick wit aren't particularly skills that the Doctor actively seeks out in his friends, but they certainly prove useful for the endless dangerous situations that life in the TARDIS presents to them, meaning that none of these characters are totally unfamiliar with what it takes to survive.
Despite being one of the Doctor's most physically capable companions following his mechanical reconstruction, Nardole's biological capabilities probably wouldn't get him very far in Squid Game. His biggest downfall is probably his willingness to trust just about anybody.
It's not that Nardole is easily fooled, but his overly optimistic and trusting personality is sure to be a weakness in a world where everybody is fighting to get each other killed. His fixation on the Doctor keeping his oath in season 10 proves that he's a stickler for rules, and probably wouldn't be willing to use his own initiative in pursuit of victory.
Similarly, Rory is a character that probably just doesn't have the ability to kill for personal gain. Through his adventures with the Doctor, he has proven that he has an extremely strong moral compass that prevents him from ever doing the wrong thing - which is a great trait to have, just not when you're fighting for your life.
The most likely hurdle for Rory is Squid Game's sacrificial marble game, where he would almost certainly give up his own life to give Amy a chance at victory. He's has proven time and time again that he's willing to do anything for her - even guarding her body in the Pandorica for 2,000 years - so it's safe to assume he wouldn't let her die just to assure his own victory.
Over the course of her time with the Doctor, Donna has learned a number of valuable skills. In "Journey's End," she even manages to absorb much of the Doctor's intelligence and consciousness through contact with his stored regeneration energy. However, the end of the episode sees Donna's memory erased, in one of her saddest storylines on Doctor Who, and everything she's learned from the Doctor is forgotten.
Without the memories of her cosmic adventures, Donna has none of the knowledge or skills that she would need to stand a chance in Squid Game. She still has her large ego and sense of self-preservation, but she's far too inexperienced to find victory.
Despite being incredibly intelligent, Bill Potts probably lacks the selfishness needed to survive in Squid Game, an environment where every player has to be 10 steps ahead of their rivals. However, her abilities acquired at the end of "The Doctor Falls" would certainly put her at a physical advantage.
Not much is known about the abilities that Bill is granted at the end of this episode, but it appears that she is able to transform her physical appearance at will. This would certainly be extremely useful for evading potential attacks and assuming the identity of her fellow contestants in the Squid Game.
Clara has all of the abilities to be one of the Squid Game's greatest threats but lacks the motivation that could carry her to victory. In 'Face "The Raven," the audience sees Clara sacrifice herself for Rigsy, which some fans think was one of the worst things she ever did on Doctor Who, a friend she'd only met very briefly a long time ago. If she's willing to make this sacrifice for somebody she barely knows, how can she be expected to make it through the deadly Squid Game?
That being said, Clara has a lot of first-hand experience with the Doctor's regeneration energy that could prove helpful to her if she found herself harmed in the game. It's never explicitly said that Clara gained any sort of powers from her journey into the Doctor's timeline, but it seems unlikely that anybody could get out on that encounter completely unaffected.
Rose is probably the companion who has the most experience with the Doctor, getting to know him in two different incarnations. They went on multiple adventures together, and she's worked with Torchwood on several occasions - most notably when she returned to her home dimension using the dimension cannon in "Turn Left."
The only thing that stops Rose from making it further up this list is that this lifestyle is now long behind her. Their separation may have been one of the worst things to happen to the Doctor in Doctor Who, but Rose is now happily living with an alternate version of him with a child together, in the comic "Empire of the Wolf." There may have been a point when Rose's odds in the Squid Game were much higher, but her transition into domestic life makes her a much less suitable candidate for the role now.
Amy might not have the same combat experience or technological know-how as some of the Doctor's other companions, but she has more than enough motivation and strive to push herself to victory if things fell in her favor. She would probably have no problem pushing others to the side in order to get what she wants, and that's exactly the kind of trait that puts her at an advantage.
The only thing holding her back is her lack of experience when it comes to fighting and her physical strength, which is lower than most of her opponents. She could easily be overpowered by one of the game's stronger players, despite her clear advantage when it comes to planning and strategy.
Of all the Doctor's companions, Sarah Jane is definitely the one that knows him the best. She's encountered him in eight different reincarnations, adventured with him countless times, and his influence on her led her to captain her own journeys seen The Sarah Jane Adventures. All this experience would certainly put Sarah Jane way ahead of the other, younger contestants in the Squid Game.
The only things that put Sarah Jane at a disadvantage here are her age and strength, which are going to make it difficult for her to complete the physically demanding tasks that the Squid Game offers. However, she's undoubtedly one of Doctor Who's most intelligent and skilled companions and should be able to put this to use in a way that pushes her to (near) victory.
Martha first met the Doctor when she was a medical student at Royal Hope Hospital, so her knowledge of medicine could definitely help her out if she were to find herself injured in the game. She also has lots of experience in battle and has worked with both UNIT and Torchwood.
As far as the Doctor's companions go, Martha Jones is certainly one of the most experienced when it comes to dealing with people (or aliens) that want to see her dead. She knows how to fight and isn't afraid to hurt her enemies in order to protect herself, which immediately puts her a step ahead of most others.
Captain Jack has the perfect mixture of intelligence, strategic thinking and physical strength that would easily set him apart from everybody else in Squid Game. Not only has he adventured with multiple different incarnations of the Doctor, but he also has endless experience as an officer of Torchwood and an agent of the Time Agency in the far future. Not to mention, he's immortal.
There's no doubt that Jack is the most physically powerful of all the Doctor's companions, even if the true nature of his immortality is still somewhat unknown. He's smart, determined and can be ruthless when he needs to be, so there's no doubt that he'd be the strongest candidate in a hypothetical Squid Game/Doctor Who crossover.