I Enlisted in My Brother’s Place, but After My Triumph, They Called Me Illegitimate?

(Historical power fantasy + decisive and ruthless + transmigration to ancient times + modern technology)

Su Qin transmigrates to an ancient world and becomes the eldest son born to a concubine in the Marquis of Yan's household in the State of Ning. Because his mother was born a slave, he has endured nothing but hardship.

Just as Ning is at war, the marquis orders him to enlist in place of his younger brother. Su Qin expects to die on the battlefield, but instead he uses modern knowledge to defeat the enemy time and again, shatter their forces, and earn one military honor after another!

Five years later, Su Qin returns as a mighty general guarding the frontier!

He thinks his parents, who looked down on him and never showed him any affection, might finally change their minds.

Instead, they order him to disappear and live under an assumed name. They want him to hand over all his military honors and glory to his younger brother, Su Mufeng!

Why should he?

His younger brother's life matters, but his doesn't?

This time, Su Qin will not back down!