I'll Be the Male Leads Sister-in-Law

I'll Be the Male Leads Sister-in-Law summary:

Today, I am a subst.i.tute for your fiancee. Tomorrow, I’ll become your sister-in-law!
Mu Mingtang is the subst.i.tute of the male lead’s first love. After she lost her family, she was adopted by the Jiang family and eventually became engaged to the male lead, the Prince of Jin.
Understanding very well that she was only a subst.i.tute, she removed her claws and fangs and turned herself into an imitation of the Prince of Jin’s first love. She couldn’t speak or laugh as she wished, she was prepared to live in the shadow of another woman for her entire life… until one day, the real Miss Jiang returned.
The real Miss Jiang was reborn. When she learned that she was the male lead’s first love, she immediately returned to fight for her engagement and ident.i.ty.
In order to please his first love, the Prince of Jin gave the subst.i.tute to the Prince of Qiyang, who had become a dying madman. She was just a low-quality fake, anyway. If she dared to anger his first love, he would turn her into a childless and powerless widow for the rest of her life.
Mu Mingtang, the target of their mockery, finally snapped: Okay, since you gave me to another man, I’ll make you bow and call me sister-in-law!
However, none of them expected the Prince of Qiyang, the G.o.d of War, to actually wake up!
—
Xie Xuanchen is the son of the late emperor. The whole world once trembled beneath his feet, but one day, for a reason unknown to even Xie Xuanchen himself, his nature suddenly changed. He became cruel and bloodthirsty, leaving his father with no choice but to pa.s.s the throne to his uncle.
Eventually, Xie Xuanchen was unable to resist the illness and fell into a coma.
When he woke up again, there was a beauty standing before his bed, looking at him in surprise. Then, for the sake of his domineering little princess, he revived his name as the G.o.d of War, reclaimed the throne, and united the world.
I once captured the world to satisfy my own ambition. Now, you are the reason for my ambition.