The Cannon-Fodder Eldest Son of a Concubine in a Reborn Daughter's Story

After being reincarnated as the illegitimate son who serves as a cannon-fodder in a novel about a legitimate daughter seeking revenge, Jian Xungui only wants to protect his concubine mother and younger sister as best he can, and keep them from making the wrong choices.

But on his very first day in this world, his identity is exposed. He's taken to the front courtyard and kept from the outside world for four years. His concubine mother has long been locked in an irreconcilable feud with his legitimate younger sister, and he himself has become the true eldest son of the Duke of Zhenguo.

His father has ambitions, so Jian Xungui offers him glassmaking and gunpowder recipes to help him usurp the throne. But along the way, he makes many friends and loses a great deal, too.