I wouldn't be surprised if he's was on the short list for Nine, Ten and the Master as well. While I don't like his role choices, he does have a mischievous quality that would make him a great candidate to play the Doctor.

She's Micah's adorable cousin and surrogate mum in season two with the power of adoptive muscle memory (what she sees, she can do), and wins for not only enjoying her power, but being the first person on the show to take to being a vigilante.