I Became a Demon for My Senior Brother, and He Didn't Escape Either

[Two male protagonists|The demon king is attacked by x human master|Slow heat|Pure love] The senior brother thought that the junior brother was out of his mind because of saving him. Who would have thought that the junior brother would become a demon for his senior brother? Eight years later, One is the demon king who is feared by everyone in the city. One is the Lord who is respected by everyone in the city. The senior brother said that he would take the junior brother home. But the junior brother imprisoned the senior brother in his dream and said: "Senior brother, don't even think about going back." Later I found out, The exchange of lives eight years ago and everything now, It's all a trap set up by my junior brother for eight years. It was all his junior brothers who were dying for him.