Adora: You don't understand, it's my destiny to sacrifice myself, I deserve to die here if it means even the slimmest chance of stopping Prime from hurting anyone else.
Catra: If you live I'll let you kiss me on the mouth.
i said it before, but i think it’s really interesting the way catra equates adora choosing to be a hero to adora not choosing catra and that being the reason she’s still so hostile after being rescued. and she says “i told you not to come back for me, but you just love feeling like a hero, don’t you?!” like, in catra’s mind every decision adora has made to do the “right” or “heroic” thing has led her away from her, even before actually becoming she ra, all the way back to being promoted to force captain while catra and the other cadets got left behind. so then when the right/heroic thing suddenly becomes saving catra, she can’t compute that in her head. it doesn’t add up, and i don’t really think it ever fully does, because that mental math comes back to bite both of them in the ass when adora accepts the heart and catra views that as once again adora choosing someone or something else over being with her.
in reality though it’s all just the complete exact opposite for adora, she’s constantly doing the right and heroic things hoping that those good deeds will come back around for catra. again, going back even to adora being promoted, she uses her newfound freedom to give a little bit to catra, stealing the skiff and sneaking out to the enchanted forest. when adora accepts the burden of the heart of etheria, she’s doing it so that she can save the world, the home that she’s finally gotten catra to be able to accept and lift up. shadow weaver actually explains adora’s thought process perfectly “if you care about her, focus on protecting her. the world needs she ra right now, not adora.” adora’s choices are always driven by love, but she thinks the only way that she’s allowed to express that love is by being selfless.
and i mean i could get into all the philosophy about “real” love and whether or not it’s selfless or selfish, but i think catra and adora themselves perfectly embody both sides of that argument. for someone who’s had everything taken from her and never had much to truly call her own, “real” love to her would come in the form of someone actively and consistently saying that you alone are my choice, all other possibilities be damned. for someone who’s had a lot of her life handed to her and always progressed or succeeded even when she felt like it was unwarranted, “real” love would mean sacrifice.
and that’s what i think is so beautiful about the way catra and adora come to finally admit their feelings for each other, because it’s a perfect combination of those two ideas! catra is ready to sacrifice and lay her life down alongside adora because adora is her choice and she will never want anyone or anything else as much as she wants her. adora, then, chooses to stay. to not let herself be taken up by a destructive force for the sake of others, but instead let herself truly come into the love she has for catra and use that as her driving force to save the world. and she does :’)