My World Traveling System: The Harbinger of Death - Chapter 11: Mana Control!

She was a medical expert, talented and beautiful. She was reborn as his little wife. Her in-laws did not like her, her husband did not love her, and she was as timid as a mouse. She was weak and easy to bully.

A young man dies tragically while trying to stop a robbery—only to awaken in complete darkness, lost between life and death.As his memories return, he discovers that he’s been reincarnated into a new world brimming with magic, Soul Weapons, and mystical powers. Reborn as Ares into a loving family, he quickly realizes that this world is far from peaceful. Armed with an SSS-Rank Trait and a Unique Ability, he faces every challenge head-on as he searches for his purpose in this strange new reality.

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

How does a half-grown mountain village boy like me end up bizarrely becoming the grandmaster out of nowhere?Source: Web...