Honestly, I'm always a bit wary when Azula and Zuko get shipped romantically. The most common trope I've seen has to be the 'redemption via forced proximity' setup, where they're stuck together after the war—maybe as co-rulers or in some spirit world exile—and the intense rivalry slowly twists into something else. Writers often explore their shared trauma from Ozai, using that awful upbringing as a foundation for a deeply messed-up but strangely understanding bond. Themes of firebending mastery as a form of intimate dialogue come up a lot, too, like their sparring sessions becoming a substitute for actual conversation.
Another huge one is the 'crown of flames' angle, where the political pressure to produce an heir or secure the Fire Nation line forces them into a marriage of convenience. It's less about fluffy romance and more about power plays, paranoia, and the slow erosion of their defenses. The best fics in this vein make their eventual connection feel like a dangerous victory, something hard-won and fragile. I've read a few where Azula's mental breakdown is treated with more nuance, and Zuko's guilt over her fate becomes a central driver, which can be compelling if handled with care.
Thematically, it's almost always a dance between destruction and healing. Their dynamic is so rooted in violence and competition that any romantic development has to navigate that minefield. I've dropped more than a few stories because the shift felt unearned, just glossing over the aggression. But when the writing captures that razor's edge between hatred and obsession, where every touch could be a burn or a caress, it's weirdly hypnotic. Still gives me the creeps sometimes, though, given their canonical history.