the most (only) important post-canon arc for mai is her learning to let herself be vulnerable. learning that she does not have to spend the rest of her life suppressing both the good and the bad - she is allowed to be sad and angry, and she is also allowed to be happy and loved. mai spent her entire life perfecting an apathetic demeanor, perfecting a persona that does not care about anything. and, therefore, turning herself into someone who not only bottles up the negative emotions but also shuts out the positive ones. at boiling rock, she finally makes a move that puts her true feelings on display, and that paves the way for her to open herself back up to all of the feelings she has spent her entire life ignoring.

post-canon, mai's arc is not only about learning she's allowed to be sad, she's allowed to be angry, she's allowed to react to the trauma she went through. it is also about her learning that she is allowed to have good things. she doesn't have to punish herself for craving affection and love. she is allowed to want, and she is allowed to want whoever she wants. she does not have to hide her feelings for ty lee, does not have to suppress her attraction to women, does not have to assume that whatever marriage she is forced into will feel like a chore at best and a life of torture at worst.

mai has gone her entire life not receiving affection. even her relationship with zuko was stilted and forced, neither of them quite sure how to show that they cared for the other because they didn't care for each other in a romantic way. it was awkward and messy, and while mai might hate zuko for running, she's also grateful because she hated it too. so when, post-canon, she and ty lee end up together, it takes mai a while to understand how to accept ty lee's affection. it takes mai time to be used to someone who kisses her cheeks, her forehead, her hands spontaneously; someone who calls her lovely and starlight; someone who will hug her whenever she needs it and also whenever she wants it. it takes mai a long time to accept all of the love ty lee has for her - to realize that she doesn't have to earn every hug, she doesn't have to be on the verge of a breakdown for ty lee to kiss her forehead, she doesn't have to spend her life trying to be worthy of affection. this affection is hers to have and to keep and to cherish and ty lee is freely offering it to her, no strings attached.

mai's arc is about learning to be vulnerable, learning to be loved, and learning to be held. it is about falling asleep next to the girl she loves and not tensing up when ty lee pulls her close. it is about mai learning to open herself up and trust ty lee. it is about ty lee's arm over mai's torso, mai's back pressed to her chest, finally, finally letting herself be held. finally letting herself be loved. finally letting herself be at peace. it is about the fact that she no longer shies away from affection, no longer fighting with the voices in her mind that tell her to break free from ty lee's arms because she does not deserve this love. for mai, vulnerability is not only crying and being angry and breaking down - it is embracing the (physical) affection that her friends and girlfriend want to give her. it is falling asleep in ty lee's arms, sleeping soundly through the night, and waking up to mid-morning sunlight, all without doubting how worthy she is to call this happiness hers.