@Gem Queen  correction
Spoiler
After killian and edith went to their territory, cliff and reeze continued with their toxic relationship but....
Cliff married another girl.
Reeze went to the monastery.
In the end.

@Gem Queen spoiler 

Killian found Edith at the train station. But they still went and explain things and that Edith was willing to be punished but it went well like in the manhwa. When she got better after fainting they went to the other territory and govern that place. The older brother and reeze got married despite her disgusting behaviour, by the way she is now possessed by the author.

The parents regrets keeping reeze in the family because she's slowly ruining the ducal family but since the ML is obsessed with her they all suffer, while Killian and Edith are doing well in their own territory. 

I think the way the manhwa is going now, it will present a better ending than the one I read. Well I didn't mind the ending since Edith and Killian got a happy ending. It's just the manhwa is making it better.

@Introvert thanks for the spoiler!!!! Is there a novel of this? I want to read.

@Aisosa Omobude try 'king of drama'. It's definitely not a cliche read but only if your into comedy and misunderstandings...