Five Frozen Centuries - Chapter 356 - Titan

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!

There’s a legendary Bishoujo Game that has become popular among Japanese gentlemen.

After his parents died, Alex Roth had a plan: become a wizard. Through hard work, he was accepted into the world’s greatest university of wizardry—but fate had another plan.

On his eighteenth, he is marked as one of his kingdom’s five Heroes, chosen to fight the land’s great enemy. But his brand is 'The Fool', worst of the marks.

Rather than die or serve the other Heroes like Fools in the past, he packs up his little sister, his childhood friend and her cerberus, then flees for the university in hope of refuge, magic and to unravel the truth about his land’s evil.

There’s one small problem: The Mark tries to ruin magic while enhancing skills outside of divinity, combat and spellcraft.…

…that is, unless he can learn to exploit the hell out of it.

What was originally an ordinary day, suddenly became a historical turning point. Enormous, mysterious Cubes appeared all over the world without warning and as if Judgement Day’s spears, inserted themselves into the blue planet.

From inside the enormous Cubes, endless streams of monsters gushed out alike raging tides, utterly defeating the unguarded armies of each state in the blink of an eye.

In order for humanity to preserve its final embers, the heads of states issued orders of retreat, to no longer attack the Cubes but rather to cling to remote cities, which they turned into self-sufficient survivor bases and around which they built 100-meter-tall Walls of Life!

Many years later, while bearing the heavy weight of history, the first expeditionary force brought back a world changing piece of information. The Cubes possessed exceedingly high intelligence and they regularly transmitted mission instructions to humans nearby. The mission rewards were incredible.

Since then, humans rushed out of the confines of the walls and once more set foot on the wasteland!

- Description from Novelupdates