Ihoujin, Dungeon ni Moguru - Chapter 28: In Search of Fame VII

A life filled with regrets.Once he realized his faults and decided to lead a new life, it was too late.His family was already gone.He had borne through each day with pure rage.Finally at the end of his misery, his wish reached the heavens—an unforgiven one.He goes against fate to raise his sword.

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!

A martial art expert from the Song dynasty lives like a Phoenix that can live again in another body after death. This time, he happened to take over the body of a Japanese high schooler who is also a victim of bullying and has a bit complicated family circumstances.

- Description from Novelupdates