[X] Seal him in a less imposing physical body, with his powers sealed as well (somewhat harsh, renders him almost completely harmless while still giving him physical freedom. Implement chibi Dazarel).
[X] Seal him in your own head. You will be his prison and his warden, and see what benefits you can gain from having a dragon chained in your body (x1.25, from, "ambitious." Middling harshness, Dazarel is as restricted as the inanimate object version but has you on hand for conversation and interesting experiences, renders him completely harmless, may or may not allow Kakara to exploit him for power).
[X] Seal him into an inanimate object. Sorcerers will be able to get him visitation, so he won't be completely alone, but he will be completely disabled (harshest, completely strips any ability to affect the world aside from talking to willing, un-captive visitors).
[X] Seal his powers away. Dazarel will still be a mountain-sized, flying, fire-breathing dragon with the ability to survive the depths of space, but he will no longer have abnormal ki and psychic abilities (least harsh, renders him within your abilities to handle if he gets out of line).
[X] Seal him into an actual house cat, because you think it's funny.
-[X] Without control of the body (harshest, Dazarel is as restricted as the inanimate object version. But in a cat. Why even?).
--[X] And then keep the cat as a pet.