I can't stress this enough. I just cannot agree with the idea of Sun willingly turning himself into Moon. If he get's pissed off enough. Because, he is popular opinion from those who say,
And agree he's mentally disturbed, and that's what he (Resort to do.) would do, kind of thing.
Yet, I feel like that's an over statement of what kind of person he is. I have a couple of things to say. That, from the book cannon, he's designed to be an entertainer.
And is a performer for young ages, and older ages. Then after get assigned to be an attendant.
Let's take one at a time, and so he's been moved over. Straight away, that is stressful.
And he felt, an a different atmosphere that would normally change the mood of someone. But for what he's going through, is different.
When he is with kids, I believe he does feel better. But, he'd never come to the point where...If he is feeling angry about something, the right thing to do is to walk away for a while. He takes himself away from the situation, he struggles to keep control.
Just so he can decompress, because he doesn't to do anything horrible. He does this a few times. When he was hiding himself from underneath the table.
When he flew himself away from Cassie, to a further away spot. So that way, he doesn't come close to her. When he tried to intervene from Moon jump scaring her.
For a character who is mentally disturbed, to do something like that. That is actually Selfless! It's minimal, but it is something big!
If he were to use Moon for anything, id think it would be for something dire. If it's a last resort thing. If he really, really needed it. Then maybe.
I typically thought he would threaten that to evil people. Not to people that he doesn't like.