I Became The Older Sister of A Regretful Male Lead

Read manhwa I Became The Older Sister of A Regretful Male Lead  / 후회 남주의 시한부 누나가 되었다
Edna possessed the older sister of the Male Lead, the man of regret, in the novel. Even the younger brother is a trash male lead who regrets accumulating all kinds of karma for the female lead, and Edna herself learns that she is doomed to die 3 years after suffering from a dark disease!
But Edna, who read the original, knew the cure for dark disease. That is, to be in constant physical contact with a person with an overflowing divine power! The only problem is that he is the 3rd Prince and the older brother of the original female lead, Karen.
Edna’s struggle to make a contract engagement begins with a natural meeting… Contrary to expectations, she will be misunderstood as a member of the group that adores Karen, abbreviated as Kalsamo!