idk which part ur not sure and im also not sure how correct i am but this MIGHT help. tbh all of this im just making it up in my own mind so im sorry if it's completely wrong.
- vampires and lycan are enemies since long time ago
- Lycan lived had adapted and lived with humans for a very long time to the point that they mate with humans and have children with them. (after this im not sure *-.-) but that makes their gene weaker as the generation goes on but sometimes there might be a jackpot and the child has a strong lycan gene.
- uke (hwagok) is somehow special (????) not sure but i guess that his lycan gene is stronger than most human+lycan child. i think that the uke has female lycan gene, that's y he's special.
- since lycan and vampires are enemies it is "impossible" for them to be mates. but somehow it works for our main couple.
- when our lycan uke found his soul mate (seme) his scent changes depending on his emotions and gets stronger when he's with the seme, i think it's probably love that makes the scent so strong. the seme also got the uke's scent probably cuz they're mates.
im sorry if they were not correct. if i said anything wrong pls tell me im also desperate to know.( ̄∇ ̄")

Can someone pls explain the things about Lycan and Vampire for me, the translation's so confusing ;;;;