The Shadowx - Chapter 5: Episode :Ash Technique, Seventh form

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction.

As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!

A generation of hegemons, betrayed by betrayal, besieged by forty-nine strong men, tragically killed and robbed the mountain, re-lived once, he will re-enter the peak; strong rise, into the chaotic star field, exhausted 100,000 strong, Wusheng dead and kill, The impact is high!

- Description from 69shu translation

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates