MTL - Afraid of My Death, My Frog Stole To the Shelter Overnight - Chapter 172

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

“On that day, Zach Harper died-” Or at least that was how it was supposed to be. I died. But there was good news, and bad news. The good news; I was reincarnated! Transmigrated into the World of Aethoria! Holy fuck, miracles do happen! But the bad news was, “Huh? What’s this?” ... [DING!] A New Quest has been issued:- Type:- SURVIVAL Name:- Quest To Becoming Stronger: Description: The {Great Calamity} is coming...Get stronger and survive. Duration-: ... Reward:- ... Penalty:- Death, ??? ] ... I had to survive.

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 fighting genius.