Return of the Calamity-Class Death Knight - Chapter 21

After I defeated the Demon King, I was executed for false accusations by the heroines.When I came back to life, this was the first thing they said.“I know it’s shameless, but would you help us one more time? Without you, the world will be destroyed.”…Would you help them if you were in my shoes?

Karl Adelheit, a self-proclaimed ordinary student returning from military service.

And a nobleman who enlisted as a soldier and received Medals of Honor.

They called him useless. A Class E farmer in a world where strength meant survival.Betrayed by the woman he loved, beaten by a power-hungry King, and left to die like trash, Isaac thought his story had ended.But death was only the beginning.Beneath the earth, sealed for thousands of years, a forgotten being awakens, an ancient force of ruin once feared by angels and demons alike. When Isaac agrees to its desperate offer, he doesn’t just survive… he becomes something else. Stronger. Colder. Hungrier.Now reborn with a forbidden power that rejects magic itself, Isaac walks the line between man and monster. Each time he unleashes the Abyssal Overdrive, his strength grows, but so does the Corruption threatening to devour what’s left of his soul.To protect the innocent, he must become the very thing they fear.To destroy the kings who shattered his life, he must embrace the darkness within.Enemies will fall. Secrets will unravel. And when the kingdom of Carreon learn that Isaac is still alive… it will already be too late.The world shunned him. Now, it will kneel.

I am merely a reviewer, albeit the products I review are slightly different. For example, I review quantum computers, artificial intelligence, anti-gravity mech armor, planetary engines, sublight colonial ships, stellar detonators, etc…