Doctor Who: Every NuWho Companion Ranked From Worst To Best
18. Nardole
Nardole brought a sardonic wit to the TARDIS during his travels with The Twelfth Doctor, keeping a sense of reality alive while also ensuring that The Doctor never got too big for his britches. He reminded The Doctor, often, of the responsibilities that they had signed up for in keeping guard over the Vault - though he must have known keeping The Doctor in one place indefinitely was a losing battle from the beginning.
Though he technically died in his opening episode, Nardole is saved by The Doctor and given an android body, allowing him to whether the adventures a little better some of the companions who came before him.
His power is in his charm, thoroughly reminiscent of Marvin the Robot from The Hitchhiker's Guide To The Galaxy. Their eventual parting displays a mutual respect between he and The Doctor, with their last goodbye offering a true sense of peace.