I have been thinking some more on Niraen's Perfection Breakdown Arc and how it grows from her Depressive Burnout Arc, and I think it'd start post-Summetset. She's already grappling with coming home and seeing it in a worse light than she remembers, realising all those 'normal' things are extremely abnormal and cruel and actually really harmful in the constant pursuit of perfection at the cost of anything and everything considered deviant and shameful. I can see Manacar playing a role in that, because she'd probably not given too much serious thought to the concept of Hulkynd beyond pitying them and having some sense of indignation that never really manifested into a productive challenge. She's read the apraxic literature, she saw the appeal, she's been all over Tamriel and now home doesn't fit.
Esterdel's fate affected her too. A young altmer woman turned against her will because she chose a different path, it is so familiar to Niraen and she fulfills Esterdel's wish to kill her because sometimes she wonders if she would have wanted her father to have had the strength to follow through and kill her too.
So she goes through all of this emotional turmoil, confronted by all the things wrong with her and her people, the realisation that Ayrenn's dream will never be fulfilled unless the Altmer change, so much pain and anguish that leaves her doubting who she is...
And she's left alone. Maggie returns to High Rock, Venaya disappears, and Niraen is forced to contend with politicians and bureaucrats to force them to accept the need to work together, then attend parties and ceremonies that she doesn't fucking care about because it's all classic altmer dress up. Smoothing over the unpleasantness and lifting up the stains so no one can perceive how deep the rot goes. And she has to do it alone because her friends bailed, assuming that she would be fine on her own. After all, she didn't lose anyone! Didn't lose the love of her life, didn't lose herself, didn't lose the entire basis of who she is and what makes her Niraen. Because Niraen is perfect and untouchable, she can handle anything.
Then in Elsweyr, Tharn contacts her over the others because she's the safe option, she's the reasonable one, she's the one who will cooperate without too much fuss. She's the annoying honorable sort, but perfection becomes her. She's less likely to kill him than the other two.
And then she snaps and punches him in the face when he tries to lay some of the blame for the dragons at her feet, as if she only went along with everything on the pretense of keeping an eye on him. And the cracks begin to show. Cadwell 'dies' and she goes on the warpath. Her emotional state suffers and she struggles to control herself - she's probably abusing the shit out of her stabilisers to prevent outright transforming, and only when Cadwell returns does she come down from her rage state, but it's now evident to Tharn that he's gravely misjudged her character and wellbeing. Once Elsweyr concludes, he essentially dismisses her from the mission and tells her pointblank that she needs to take time and get her shit together because if she breaks down, she is going to have an impossible task in putting herself back together.
You know it's bad when Abnur Tharn sees your suffering and doesn't snark about it. It's even worse when he offers words of comfort. Brusque Tharn-style comfort, but more comfort than anyone's offered you since you were a child, because comfort couldn't be afforded. You had to be perfect, you had to be in total control, and comfort suggests you slipped, and slips are fatal where the Divine Prosecution is concerned.
So Nirri goes off, not knowing what the fuck she's supposed to do now because she's alone again and Abnur fucking Tharn has called out her one weakness and vulnerability and told her that she needs to find a new sense of self or at least a foundation for a healthier one before he'll let her help again. She goes through the Lycanthropy Arc with Moonhunter Keep, meeting Narazda and beginning to wean herself off of her stabilisers in favour of building her new sense of self as a more consistent means of control. Not rejecting the Beast so hard that she requires potions but letting it breathe so that it doesn't need to claw its way out.
Then it's off to help Kasura and reuniting with Sai to get back in on the Dragon Problem, and she finds herself coping far better for longer. And Sai notices the change in her. He notes that she seems better balanced now even with her rougher edges. It's good. She seems better, healthier, maybe even happier. Bonding with Nahfahlaar and embracing her wolf and being generally more free with herself, Dragonhold is where she begins to really shed the persona of pure perfection, but all the while she's so very aware of how far removed she is from her friends. She still feels alone and isolated from them but doesn't reach out because maybe they don't want her to. Maybe Summerset drove them away for good, or seeing her would only bring back painful memories.
She wants to be generous to them. She knows they've both suffered too, and doesn't want to put her problems upon them... but Tharn saw her problems and told her to prioritise herself for once. When was the last time anyone told her she could do that? Who else has ever told her that she didn't need to be perfect, she needed to be whole? It doesn't feel fair that they always got to be messy while she always had to be the perfect one.
So while her Burnout Arc is resolved by the end of Dragonhold, her Perfection Arc remains simmering in the background. Gates of Oblivion pokes at it when she reunites with Venaya, but it's only on Solstice where it really rears it's head in full because she's surrounded people who just assume that she's perfect, untouchable Niraen. The Fighter's Guild Champion, the Hero of Coldharbour, the one who champions Auri-El's light and blazes like the sun. And of course, Kyriel and Orion (mostly Kyri) keep rubbing salt into the wound with snippy remarks.
But then that sun burns them during the Writhing Wall and she turns around and snaps at them all. Because none of them fucking know her. None of them were there when she was broken and hurting, none of them saw how deep that pain went or how badly she needed help. It took Abnur fucking Tharn noticing what was wrong for her to start rebuilding herself from the shell she was hollowed into by her condition, by her father, by everything the world has put her through, and the rest of them only want to know her when she's useful to them. When they need to be healed or they have a problem that needs solving. None of then want her, only what she can do for them.
Who protects her? Who heals her?