read it if you're reallyyy sure because I don't want to ruin the experience of reading the manhwa
it's horrible, Ian was sold since he was very young as a sexual slave to the Southerners, and the one who bought it was Michele's father, who sexually abused him during that time because he couldn't have sex with his wife who was pregnant with Michele at the time. (And if I remember correctly, one of Michael's brothers somehow abused Ian).
To be very vague and avoid spoiling the experience, Ian wants revenge on Michael's family, including Michael himself. Ian's life is a complete tragedy where the only good thing in the end is the son of the man who abused him all his life.

I get it if you want to share spoilers but here's some tips~
- DO NOT type Spoiler at the title section and continue your 'spoiler' right at the comment box
**your Spoilers aren't concealed at all.you'll ruined the mood to those who avoid spoiler at all costs.
-DO write Spoiler Alert at the comment box instead then leave some blank space like about 10 spaces to start your spoiler there
** it's all about etiquette people~
You don't go to a movie and said 'ooo~ I watched it before.The hero gonna die at the end~' right when the movie starts
Peace out~ ε=ε=(ノ≧∇≦)ノ