Hide and Kaneki have this intense friendship that often gets completely shattered by the shift in power dynamics after the Anteiku raid. I've seen a lot of writers latch onto the central tension of Hide, the totally ordinary human, trying to reach a Kaneki who's now a terrifying ghoul king. The core conflict usually isn't about physical danger, but about whether Kaneki can even recognize the person who cared about him most, or if he sees Hide as just another fragile thing to protect by pushing away. It's brutal, because Hide's defining trait is his relentless, cheerful loyalty, and watching that optimism get systematically crushed by Kaneki's coldness or violence is where most of the angst lives.
Some fics take a different route and make Hide the proactive one, like he's doing detective work on the side to track Kaneki down, which adds a layer of conflict where Hide is actively deceiving the CCG or his own friends. The moral ambiguity there is great—how far will a normal person go for someone who might not even want to be saved? I think the most heartbreaking ones are where the conflict is internal for Hide, wrestling with the fear that the friend he loved is truly gone, replaced by a monster wearing his face.