I am Beelzebub, the King of the Devils that stands tall over all others. But after being betrayed by my subordinate and killed, I was reincarnated. I was definitely supposed to be born again as a devil…! But I can’t even spea… ababubaba…! The almighty Beelzebub is now a human child?!

(Source: MangaDex)

Don't let your human scent linger.
The intense story of Phantom Highschool, starring Ingan Kim who was just placed as the homeroom teacher of room 8!

Who knew that the game I designed for fun with my friend in middle school would later become a monster that would swallow up the entire world?Taejun, who has been living a tough life with his younger sister, loses all of what he saved due to a lease fraud. In despair, he curses, "To hell with this fucking world!!" while looking at Namsan... but the next day, the curse came true!Namsan suddenly turned into a large sinkhole where man hunting golems started endlessly spawning!! The world has turned into a living hell, but Taejun realizes that these golems may be a mob he created in the past? A strategy that only he knows of. Save the world, or save just yourself.(Source: MU)