Hokuou Kizoku to Moukinzuma no Yukiguni Karigurashi - Chapter 29 — A Sudden Visit

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

The protagonist is reborn at the end of the Roman Republic, becoming a gladiator under Spartacus. How will he escape the tragic fate of being crucified and survive in the Mediterranean under Roman rule? Stay tuned!--------------Rome must perish! As long as it exists, we find it difficult to escape the fate of death! —Maximus

'Death' It was meant to be the end, but it brought a new start.After a destructive nether storm consumes his world, Jack finds himself face-to-face with a powerful being who tasks him with a mission he can’t refuse.Reincarnated as Asriel—the most tragic, doomed character from a novel he once read—Jack’s frustration grows: “Damn it, why this fool?”Now, he must navigate Asriel's cursed life, facing relentless supernatural beings that threats him with a single hope:[Necromancy System Activated!][Ascend as the Ruler of the Undead!]But can Jack rise above Asriel's fate, or will he, too, fall prey to the shadows lurking in his new world?

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……!!