MTL - Longevity Begins with Jinyiwei - Chapter 15 young hero

After transmigrating into a beast world, Rong Mingshi discovered that the people of this world experienced widespread mania. For example, when their emotions were abnormally agitated, they would become destructive beasts. If their emotions were abnormally low, they would shrink into their young beast form.

A good-for-nothing man married a beautiful girl but was kicked off the bed on the wedding night. Furiously, he wrote a bill of divorce and ran away.
He was schemed a car accident in which he nearly lost his life. However, it turned out to be a blessing. He swallowed the soul that passed through the outer world, thus obtained superb medical skills and martial arts.
Later on, with the silver needles and invincible martial arts, he embarked on the road of counterattacks and was committed to his great dreams.

- Description from Novelupdates

The Jiuzhou Continent contains an era of chaos and fiendish demons, haunted by mysterious beings and fraught with feuding martial families, demonic sacred grounds, and endless struggles between various powers. Conflict is a constant throughout the world.Within such darkness, Gu Chen opened his eyes to this reality.At the same time, he discovered that as long as he slew these fiendish demons and ghosts, his cultivation strength could continually elevate.Killing a Panic Level Demon yields a decade's worth of cultivation.Slaying a Ghost Level Fiendish Ghost brings thirty years of cultivation....Eventually, one day, staring at the endless swarm of fiendish demons and world-renowned grandmasters in his path, Gu Chen chuckled lightly, “Are you able to withstand this fist of mine, charged with 1600 years of cultivation?”

The Principality of Atall lies between two great powers: the Kingdom of Allion to the west, and the Holy Dytiann Alliance to the east. Leo Attiel, the second-born prince, was sent to Allion as little more than a hostage, where he studied and trained in the military arts under a frontier general. And now, the times have reached a turning point.

Relations between Allion and Conscon Temple, a neutral land adjoining Atall, have worsened. Percy, sent from Atall as reinforcement; Camus, a warrior monk; and Kuon, a mercenary from a remote region, join forces to resist the looming threat of Allion’s army.

At the centre of the fighting, the three of them and Leo are about to have their fated encounter.