MTL - Tokyo Literature and Art Times - Chapter 431 life thorn

Our protagonist Caam is a man from Earth that was reincarnated into this world as a demon. In order to survive, he spared no effort in avoiding the sparks of battle and without noticing it, he became strong himself.

HE WAS SUPPOSED TO AWAKEN A POWER. INSTEAD, HE AWAKENED NOTHING.Louis Lee is the son of two legendary Earth Defenders, but when the superpower evaluation test reveals that he's powerless, his world crumbles. Mocked, abandoned, and broken, Louis becomes a target in a world where strength is everything.But fate has other plans.When a devastating alien invasion shatters the city, Louis is abducted by the same monsters that once killed his parents.Subjected to a brutal experiment, Louis is implanted with a living alien core, a weapon to annihilate humanity at once but instead the core grants him incredible powers making him, half human and half monster.But now, Louis is Earth's only hope of defeating the invaders, but the more he uses the core, the more it mutates him, transforming him into something far more scary.

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates

Police officer, would you believe me if I say this is an Iyashikei game?