Bruh from the beginning since it seems in this universe they dont even understand exactly what it is fully yet, you can tell from how sparse the production of omega medication is in the pharmacy, Muwon probably has an idea since he’s experienced it to a certain extent but I don’t think they even have enough medical knowledge on this, hence why the hospital isn’t your best shot, seems like the start of how the ABO universe came to be

I still don’t get why bro couldn’t just be like “uhhhh wanna go to the hospitalll??” To prevent this his heat