From Runaway Bride to Global Queen - Chapter 173 - : Promoted to Manager

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!

Alvaric Zorvok, an ordinary young man who desperately wanted to become an Awakened. But when that moment finally came, he was instead summoned to a strange world—a desolate land filled with all kinds of monsters.His life became a struggle, and he came close to death countless times.Slowly, he climbed his way up and became one of the most feared beings in that world.“Can I ever return to Earth?”Alvaric didn’t know when—or if—he could go back. All he could do was fight, explore, and search for a way home.

Science and magic exist side by side in this world.

This is the peak of the science side with a curriculum for espers, Academy City. In this city where 80% of the population are students, the season has finally come when all residents are excited and fidgety!

It’s Christmas Eve.

Amidst the city showing a cheerful hustle and bustle, ordinary boy who can’t keep up with school, Kamijou Touma, also doesn’t intend to miss this event! He was hard at work in his supplementary lessons…

A backward glance from the default misfortune-prone bastard, the silver-haired sister freeloading in his dormitory, Index, in the heart pounding scene different from the usual, activates a new gluton skill!? While Kamijou tries to desperately stop that, Misaka Mikoto taken in by the Christmas Eve atmosphere appears before him.

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

- Description from Novelupdates