Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 16 - 16-76. Saga Empire, Battle at the Imperial Capital (6)

A single distrustful phone call to the authorities led Ling Ke, who had crossed over to the eve of the Third Honkai Eruption, to endure years of torment as a lab rat.By now, the Crimson Herrscher had already “transcended,” Kiana was with Anti-Entropy, Mei was with World Serpent, and Bronya had long since reunited with Seele...As for Ling Ke, he had become the Herrscher of Dominance, commanding a thousand puppets.“From this moment on, I will exact my revenge upon this world!”The once ordinary Chinese man who had crossed over into this world, now completely consumed by darkness, revealed a terrifying, twisted grin.A forewarning—this is not a happy story.

A young Brave walked out of his village, gathered companions to his side, defeated the Great Demon King, became famous, then came back with beauties in hand! This was a legend that appears in the world of Seyrol every 200 years!

Our protagonist, however, isn’t a Brave. Even so, for over a thousand years his figure has loomed throughout its history.

Unwittingly, the name of the Red-robed Priest began to resound throughout the world. Red-robed Priest’s legend included extraordinary sword techniques and magic, erudite knowledge, and an almost prophetic ability to lead young Braves toward the proper path. People of the world think of him as a descendent of the ancient Yellow Race which led to his omnipotence. In essence, however, this was just the characteristics of the profession known as ‘Noble’.

- Description from Novelupdates

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!