Karkat and Dave are one of those pairs where the fanfic can't help but dwell on different kinds of struggle. There's this constant push-pull between Karkat's volcanic, unfiltered emotional honesty and Dave's detached, irony-shielded repression. A lot of stories zero in on the tension of forced vulnerability—scenarios where Dave's cool facade finally cracks, maybe because Karkat wears him down or a crisis makes it impossible to keep up the act. That moment of genuine, unguarded feeling, often anger or fear or sudden affection, is a huge emotional payoff.
Another recurring thread is about mutual misunderstanding turning into a weird, specific understanding. They speak completely different emotional languages, so fics love to explore how they eventually learn to translate. It's less about grand romantic declarations and more about actions—Dave making a perfectly timed, understated gesture, Karkat yelling his concern through a rant about something else. The theme isn't just 'opposites attract'; it's 'these two specific, damaged kids from a terrible game learning to be less alone together,' which carries a lot of weight for readers who connected with that aspect of 'Homestuck' itself.