4. The Dream Lord
The Dream Lord would come lower on the list because it is so very nearly an idea that is contained to a single episode. Hes a manifestation of all of the dark emotions of the Doctor and wrecks havoc upon him, Amy and Rory by throwing them between two worlds with the challenge of finding out which one real. The storys conclusion, however, appears to wrap up quite conclusively when the Doctor proves both worlds to be dreams as the Dream Lord should have no power over physical reality and the cause of his manifestation is psychic pollen which landed in the Tardis time rotor. The end of the episode, however, does hint that the Dream Lord can never truly be defeated but rather will lie within the Doctor, primed to return again. Toby Jones performance as the Dream Lord was so good it deserves a comeback but the story possibilities bring some restraints that cant always be worked around (the mystery who he really is has now gone and his powers have to be in an imaginary world). So how do we solve these problems? The Dream Lord returns when you also bring back...