Okay, so talking about 'Royai'—Roy Mustang and Riza Hawkeye from 'Fullmetal Alchemist'—their fanfiction gets its emotional weight from a few deeply ingrained themes. It's a world built on professional distance and unresolved history, so a lot of the stories are about navigating that. The most prevalent theme is this suffocating, silent devotion, the kind where they're willing to die for each other but can't bring themselves to say anything. It's less about grand romantic gestures and more about the tremor in a hand while reloading a gun for him, or the specific way he stares at her back when he thinks no one's looking.
Then there's the guilt and atonement thread. Roy's ambition and the Ishvalan Civil War hang over everything. A lot of plots explore him grappling with his past sins, with Hawkeye as both his witness and his anchor. She's the one who has seen the worst of him and still stands by him, not to absolve him, but to ensure his goals are worthy. The emotional climax often isn't a kiss; it's him finally breaking down and her being there, not with forgiveness, but with a steady, quiet presence that allows him to keep going. The romance feels earned because it's woven through this fabric of shared trauma and a painful, slow-burn journey toward a future they don't feel they deserve.
You also see a lot of 'domestic after the storm' scenarios—what happens after the Promised Day, when the immediate danger is gone but the shadows remain. The tension shifts from survival to figuring out how to live. Can they lower their guards? How do you transition from a military chain of command to something like equals, or lovers? The fics that handle this well focus on small, awkward intimacies: sharing a room and not knowing how to sleep without a weapon, or a conversation where they actually talk about Ishval without one of them shutting down. The emotional payoff is in those fragile moments of normalcy, which feel like the hardest battles they've ever won.
Ultimately, I think the core emotion is a profound, weary loyalty. It's not flashy. It's in the way she adjusts his coat before a public speech, or how he uses his political power to quietly protect her reputation. The themes are less about passion and more about a deep, aching partnership that's been forged in fire and duty, and whether that can ever transform into something peaceful and openly loving.