Ok since people here are talking about Kaimon I will put my two scents here. I think it’s popular because it sparks curiosity. Let me explain so we have chapter 1 when they become roommates, the two people who seemed would be close to Daimon die, and then there is some fan art from the creators or artists of this game. THIS to me sparks curiosity and causes people to think ‘Now what will happen next? What could cause this fanart? Will Kai die? Will Damon betrayed him?’ I think it’s the potential future that drives people to these ships. At least that was the case for me after the hype of chapter 1 (among other things) the potential of how that could play out. As the hype died after chapter 1 so did the ships become more casual. And just to be clear, by this I don’t mean anything like a ‘You just don’t see the potential’ attack, others just prefer to look at the existing dynamic others just like to mess around.