Maybe it's because I'm a sucker for found family tropes, but the best fics about Hu Tao and Zhongli aren't the ones that amplify their differences—they're the ones that find the quiet space where those differences stop mattering. I've read a dozen where she's dragging him to some weird festival and he's giving a five-paragraph lecture on its historical inaccuracies, and yeah, that's fun for a bit. But what sticks with me is when the story slows down. Like, there's this one where Hu Tao finds him on a bench in the harbor at like 3 AM, just watching the lanterns. She doesn't make a joke. She just sits, and he starts talking about erosion, not in a grand 'I am a god' way, but like he's tired. And she listens. That's the dynamic that fascinates me; her frenetic energy isn't always a counterpoint, sometimes it's just the thing that fills the silence he's lived in for centuries. He's stability and memory, she's chaos and the present moment, but in those stories, they meet in the middle where both of those things are just... lonely. The contrast becomes the reason they can understand each other, not just banter.
That said, a lot of writers do lean hard into the comedy, which can feel a bit one-note if it's not done carefully. The 'grumpy old man and his hyperactive gremlin daughter' tag is basically its own genre. It works because it's rooted in their canon dynamic—her constantly trying to get a rise out of his impeccable composure. I've seen fics where she teaches him memes, or tries to get him to endorse the parlor on social media, and his deadpan responses are golden. But the ones that really nail it also remember that Hu Tao isn't just 'random.' Her obsession with death and the afterlife is philosophical, in its own way. So when Zhongli responds with actual, millennia-old wisdom, it's not just him being stuffy; it's two different kinds of understanding the same profound truth colliding. He's seen it, she theorizes about it. That's a much richer contrast than just 'loud vs quiet.' It makes their friendship feel earned, like they're the only two people in Liyue who can actually have that conversation, even if her side of it involves ghost jokes.