There’s a lot to unpack when comparing Misty to Tempest, and I’m glad I shelled out for that screenwriting book.
First, we need to talk about conscious desires versus unconscious desires. A conscious desire is the goal a character is actively thinking about. Unconscious desire is what the character “actually but unwittingly wants”, and is in conflict with their conscious desire. A lot of stories involve a character sorting things out and deciding on what they really want.
Tempest is an anti-villain, which is a character with positive traits, goals, and/or virtues, but who acts destructively. She’s The Storm King’s cruel and sadistic enforcer. She is also polite, professional, respectful, a good leader, she gets results, and she has worked hard to overcome her limitations, which are all admirable qualities. Consciously, Tempest wants her horn back, and to be feared and respected. Unconsciously, Tempest wants to be accepted, to not be helpless, and to not feel like a freak, which are positive goals. She is the protagonist of her own story.
Once Tempest connects with her unconscious desires and sacrifices all the benefits The Storm King grants her, she has completed her Hero’s Journey and deserves to enjoy the fruits of her self-improvement.
Misty is also the protagonist of her own story, and a villain. Misty is endearing, but it’s interesting to note that when you get right down to it, she doesn’t have any positive qualities. Tempest is really good at her job, reaps benefits of the position, and gets to indulge her sadistic side. Meanwhile, Misty has no business being a villain. She’s clearly uncomfortable with the things she had to do, and it’s implied she doesn’t even get enough to eat. But she’s never known anything else.
At the start of Chapter 2, Misty doesn’t appear to have any unconscious desires. She’s motivated entirely by pleasing Opaline and getting her cutie mark. Towards the end of Chapter 2, we see that thanks to her interactions with The Mane Five, she is starting to develop unconscious desires for a real family. Misty is willingly going along with Opaline’s plans for her own personal gain. However, you can also recognize that Misty is being manipulated. She doesn’t deserve a cutie mark, but she deserves better than life with Opaline. Even if Tempest never got redeemed, she would still deserve a better employer than The Storm King.