Unlike Ashildr the Vikings and the Mire exist solely for comic effect. After the warriors are taken the Vikings are portrayed as sweet and goofy buffoons who mean well but are entirely ineffectual. The Doctor doesnt even bother learning their names as hes certain they are all doomed. Ashildrs father is the only one who comes close to a fully fleshed out character and even he is little more than a prop for his daughters actions to bounce off of. While their antics are amusing its hard to care about such superficial characters and thats too bad as the plot sinks into mere melodrama. The Mire fare no better. The lead villain, masquerading as Odin, is little more than a Monty Python gag. He does nothing but posture and is given no motivation at all. The electric eel reveal is ridiculous but that could be waved away if only the character dynamics were more interesting. Next to Ashildr the best drawn character is the barely scene baby that is only known to us through the Doctors interpretation. The words of the baby are startlingly poetic and filled with melancholy and poignant confusion. Peter Capaldi speaks for the child with a quiet reverence that pricks at our emotions.