Omg fun question, thank you so much ;_; !!!!!!!! I focus more on Tsukasa's feelings than Rui's because pov and all but I try to make everything obvious as well through his movements because they're all very intentional and if it's not Rui you won't be able to read him as such. That's just how I write him though, as far as hcs I take into consideration there are probably too many but the obvious is I write him having ASPD (unpopular take but I stand by it), and in my Tsukasa fics even though I see him as a gay man straight up I also see him as Tsukasasexual which I need everyone to know. She has fixed him, if you will