From A Stronghold NPC To The Final BOSS - Chapter 1116 - : The reason

In order to chase down and kill her own murderer, Xia Yichu reached an agreement with the 233 system, and she will travel through the world to complete the task, and The 233 system helped her return to the original world.
However, Xia Yichu often encountered a broken BOSS while he was on his way to do the task. He did n’t agree with each other on the wall, the bed, the various patterns, and kept talking.
System: Please use one word to describe the other person’s impression in your heart.
Xia Yichu: Competent.
Shen Jiaye: Mine.

- Description from 69shu

Transmigrating into a mystical and eerie world, Fan Wu gains a special ability: a system to allocate attribute points! By slaying demons and monsters, he earns points to enhance his own attributes!From then on, a peculiarly muscular Taoist priest appears in this supernatural world.Facing trembling demons and monsters, Fan Wu reveals a ferocious grin.“Your purity is too low!”“System, enhance my stats!”

The world I reincarnated into was a world that enabled you to use magic after having read a Grimoire.

And the Grimoire’s contents areーー you wouldn’t believe it- it’s 「Manga」.

This world’s people would take around a year to read a single Grimoire (Manga)

While for me, it would not take an hour, as it was「Manga」

Interpreting and understanding all kinds of Grimoires, the 6 year old me who became the World’s Strongest Master Mage, welcomed brides that were also 6 years old, and started living a carefree life……!!

He was about to join the beta test on the newest VR games, Second World.

But an anomaly threw him into a world with familiar rules, a rule he usually only experienced in a game.

Now he must use his past gaming experience in this new world.

It was no longer a game, it was survival! A strive to reach the highest level possible.

Equipped with dual-class of melee and magic user, John was set on the path to become the strongest character in this brave new world.