I Fell into the Game with Instant Kill - Chapter 54.2: Hallmenta (5)

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

Corvin Blackmoor was a man carved by war and betrayal.From the blood soaked deserts of Afghanistan to the shadowed corridors of British Intelligence, he served and watched ideals crumble into lies.Patriotism. Honor. Loyalty.He buried them all long before a Quds Force assassin silenced his final breath.But death was only the beginning.Dragged from the ruins of a dying world, Corvin awakens in Valtheris. A savage world ruled by magic, where gods are myths, and survival is written in blood.He is no longer human.He is the last of the Dark Parasytes, an extinct race once so feared that every kingdom, every empire, and every mage order hunted them to extinction.Armed with Shadow Siphon, the power to replicate the strengths of others, Corvin stands alone at the bottom of an alien food chain.Weaker than a wild beast, with enemies and predators lurking in every forest, every court, every throne.Weakness is temporary, patience is eternal.In a world fractured by ancient wars, between noble Elves, scheming Demons, ruthless Humans, primal Feralis and Aetherborn Corvin will climb.He will feast. He will conquer.And in the shadows of Valtheris, the last predator will rise.No gods. No masters.Only the cold ambition of a man who has nothing left to believe in… but power itself.

This novel is about the young master of the Du clan, Du Shaofu, who was born with crippled veins and is unable to cultivate martial arts . After finding out about his situation from the clan while returning home he got hit by a lightning and a mysterious ‘first scripture’ appears and after studying for ten years he was able to mend his crippled veins together and starts his journey to glory.

I finally managed to kill the demon lord.