Read manhwa Tamed A Blackened Slave Man / Taming a Corrupted Slave Man / 흑화한 노예남을 길들였다
In the future, I succeeded in taking the man who would become the best in swordsmanship, one step ahead of the Prince and enlisting him as my younger brother. I treat my younger brother, which is not blood related to me, more kind than anyone else, and I fed him well and raised him well. He will be my younger brother who will protect me from the damn fiance who killed me in my previous life, and will be the replacement to go to war on my father’s behalf. “I have never thought of you as a family from the moment I first saw you.” “My dear sister.” His eyes, filled with possessive desires, shone. It was a beast that I brought as my younger brother.