MTL - Douluo Dalu - v5 Chapter 169 Master is the devil (below)

After the Calamity War, the final and most devastating conflict to decide who would claim the Divine Throne, Kael Medici stood as the last survivor.He had led armies, fought with unmatched ferocity, and performed legendary feats. Yet in the end, his fate was no different from the rest. He perished like all the others, the final casualty of the Great War, his hand just shy of the throne he so desperately desired.But when he thought it was over… his eyes snapped open.He had returned to his youth, his memories intact.The path to divinity is drenched in blood, and the battle for supremacy is merciless. Yet Kael has already endured this once. This time, failure is not an option.With the memories of his past life, dominating talent and and a mysterious power awakening within him... The preparations to reach the Divine Throne were complete.

Struck down amid the battle, the Hero and Demon King meet their demise. As their souls linger on the edge of the afterlife, a mysterious force intervenes, merging their fragmented souls together with a new being. Rusty, the living armor, now affected by their memories and presence, embarks on his own quest. Will he seek revenge on those who betrayed the hero, or will he fulfill the desires of the fallen demon king? or instead, forge his own path?

Calamity descends upon a a tranquil world in the black of night, transforming it into a death game! This a a true apocalypse, but this is not the end of humanity!

- Description from Novelupdates

“If I don’t die… I swear I will act on all my evil thoughts..”

Not exactly everyone’s typical thought when they’re about to die. What will a cowardly young man do when reincarnated with the evil powers to redefine his destiny? Can the natural kindness of human nature triumph over evil? Will he become the cold-blooded demon king of legend, or will he forge his own path and rain down another kind of terror?

- Description from novelupdates