MTL - Bastard Male Wife - Chapter 7 Find the difference

She fought in the Battle of Changping and witnessed the killing of hundreds of thousands. She once led the Qin Iron Calvary and battled against the Six Kingdoms. She has seen a third of the land and witnessed the breaking of mountains and rivers. The sound of a grand zither and the light of a great female emperor. A prosperous world that was forged on the battlefield. Yet, these two thousand years are forgotten from history.

- Description from Novelupdates

ICUWSA, the most popular web novel with the most loyal fan base that could be mistaken for an occult group.Out of all those fans, Seoyoung could proudly say he was at the top. But everything comes crashing down in one chapter.Just his normal boring day life but one chapter was enough to distort it.The death of the Protagonist. This one fact makes Seoyoung furious and he decides to abandon his boring life.“Today will be different.”As soon as Seoyoung calls his boss and quits his job, a new breath of life fills his lungs, but not for long.The world glitched, and in the next moment, he wasn't there anymore.“Where am I?”He wasn't on earth anymore; he was in the body of a no-name character in the first arc of his favourite novel.Noctis Academy.Just another extra like him, destined to live normally and maybe die after the academy.But he is determined not to live by the story but to break out of the shell of society and live a life worth living.“Just another extra. No, I don't think so.”Given a second chance at life, Seoyoung, now Kaiser Vanguard must navigate his way through this new world. Breaking the chains that bound him. While questioning the reason for this new life.“You can start the journey from the auxiliary chapter.”

The strongest Demon Lord dies, and reincarnates as a human. Not only that, he because of various incidents turns into the hero’s best friend.

Follow his journey as he tries to help the hero escape his fate, and on the sideline to conquer the continent while he’s at it.

He, without doubt hates her.
What did she do to deserve his hate?
The person who she treated well like a brother did not even bother to notice it...

Years passed…

He needs to get married.
He needed a wife.
So she offered herself.
It was a marriage that will benefit both parties he said.