Roy lived an ordinary life—nothing remarkable, nothing worth remembering. That is, until his final moments, when he sacrificed himself to save a mother and her child from a reckless, drunk driver. But instead of the afterlife he expected, he awoke… as an egg. “What the hell? Is this some kind of joke? Did I end up in Hell instead of Heaven?” Reborn as a demon in an unfamiliar realm, Roy discovers the Custom Demon King System, an ability that lets him bring to life anything he can imagine and design—at the cost of souls. Armed with this power, he sets out on an adventure across countless worlds, forging his own path as a being feared by gods and demons alike!