There’s a lot more extreme bdsm stuff than scat… he could be inflated, enema kink, fisting kink, cuck kink, piercing kink, needle kink, cutting kink, etc. And you say that a manhwa wouldn’t but I’ve seen all of the above in a BDSM yaoi manhwa and this is a BDSM ecchi Josei(?) manhwa so I don’t think it’ll be that different in terms of what you can and can’t show.
You don’t think needle kink is more extreme than scat??? Okay bro. Scat is the one that’s the most NICHE I will give you that but it’s definitely NOT the most extreme. I saw someone get a giant needle pit through both tits. You cannot say scat is more extreme and uncomfortable to see than that. Any dangerous or possibly unsanitary BDSM act could be considered “extreme”. That’s just how that works. And it’s not the first time I’ve seen in a manhwa, a dom teaching a sub how to enema and doing it for them. We don’t SEE the stuff that comes out but you KNOW stuff came out.

… people think we will get scat in a manhwa, LOL. The worst a manhwa would do is watersports.
But I’m pretty sure that it’s just going to be good ol’ pegging.
Also, seeing Richard cross-dressing unlock a new desire in me. I want him to get to indulge his clear exhibitionism kink but too bad he’s a crown prince.