i have way too many and not enough properly jotted down so i also like. forgot half of them. but the headcanon that is most important to me is karkat having autism. i got diagnosed either halfway through reading homestuck or shortly after finishing it and the first thing i did after the fact was declare to my friends that karkat is autistic LOL. i relate to him a lot so projection is inevitable, a lot of his traits like having shit emotional regulation and being bad at communicating/forming proper healthy relationships or even his dislike of Going Outside (mostly in the epilogues, sensitivity to light even) read as autistic to me, even if some of them can be explained away via troll societal reasons