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

Mu Mingtang, adopted by the Jiang family, becomes engaged to the Prince of Jin as a substitute for his true first love. Aware of her position, she suppresses her true self, meticulously imitating the original woman. Her life of living in another's shadow ends when the real Miss Jiang, reborn, returns to reclaim her engagement and identity. To appease his first love, the Prince of Jin bestows Mu Mingtang upon the seemingly deranged Prince of Qiyang, deeming her expendable. Enraged by their mockery and mistreatment, Mu Mingtang resolves to make them call her sister-in-law. Unexpectedly, the Prince of Qiyang, the formidable God of War, awakens. Once a powerful ruler, Xie Xuanchen had descended into a cruel madness, losing his claim to the throne. Upon waking to Mu Mingtang's presence, he is inspired to reclaim his former glory, revive his reputation, and unite the world, with her as his driving ambition.