Naze Boku no Sekai wo Dare mo Oboeteinainoka? - Volume 1 Chapter 2 part3

Damian, a Centurion of the Punishment Unit of the Baroque Kingdom. “Damn it.” Just once. If I were given just one more chance… ‘I would have truly conquered the battlefield with these guys.’ At the age of 30, he closed his eyes on a nameless battlefield. But when he opened them, he found himself back 17 years in the past. And this time, he had a perfectly functioning mana core that could wield magic. ‘This time.’ I will rise higher than anyone else. I won’t be swept away by the turbulent times. ‘I will conquer.’ Damian, who has returned to the past, wields his spear toward the world.

Unrivaled Spear Knight.

The stereotype that knights must use swords is broken by the brightest star of a duke’s family. The hero that brought an end to the empire’s civil war. The name of that person is Joshua Sanders.

Despite his reputation of being called the empire’s unrivaled spear, he was bleeding dark red blood. Not just anyone but by the hand of his own emperor, Kaiser… “Kaiser! Don’t think it will end like this!!” Moments before death, incurred by magic circle, the spear that spent its years together with him, ‘Lugia’, started to emit an enormous amount of energy…

This familiar place, it can’t be… the stable that I used to live in when I was young?

My body became young?! Lugia, what the hell are you?

Joshua returned to his younger self. His ultimate revenge starts here!

Thirty-three classmates hold a reunion after graduating. Tensions soar and old friendships are tested, as a strange turn of events lead them to follow the path of the ancient gods.

“There is a scar on my stomach which is hard to heal over the years”..

Ning Yu is forced to marry Song Bai Lao, whom he was deeply entangled as a teenager. Because of the misunderstanding they had before, Song Bai Lao keeps bad-mouthing Ning Yu to the point that he even becomes Ning Yu’s nightmare. As they get together, Song Bai Lao finally confronts his feelings for Ning Yu, and Ning Yu finally sees his true feelings and sincerity.

- Description from Novelupdates