Merlin: Vacant
Prince Arthur: Vacant
King Uther: Vacant
Gaius: Vacant
Morgana: Vacant
Guinevere: Vacant
The dragon: Vacant

(If I've missed any others, please comment below)
Also, you shall be required to post a three sentence long roleplay comment below, as your chosen cannon character. I want to make sure that you will play said character well, and not out of character.