Golden Time - Chapter 147

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.

Ryo Tanaka, a struggling college student, works tirelessly at multiple part-time jobs to make ends meet. In a bid to earn some extra cash, he volunteers for a paid drug research study, unaware that it will alter the course of his life forever.The experiment takes a disastrous turn, leaving Ryo bedridden with a high fever for several days. But when he finally awakens, he finds himself in a world plunged into chaos. A deadly virus has ravaged the city, turning its inhabitants into ravenous, flesh-eating zombies. Streets once bustling with life now lay desolate, the remnants of civilization crumbling under the weight of the apocalypse.

More than ten years later, this sentence gradually spread in Elbaf Continent:

Never use magic to deal with tyrants, because you will find that he will return your spells to you thousands of times after being strengthened by countless magic specialties.

This is the story of a dragon-shaped self-propelled fort that keeps doing things in another world.

There is nothing that one magic can’t fix. If there is, then there are more. ——Izawa

- Description from novelbuddy

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!