I'm at Level 30, But I Can Slay Level-9999 Beasts in One Hit! - Chapter 231: Showing One’s Claws

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

I am merely a reviewer, albeit the products I review are slightly different. For example, I review quantum computers, artificial intelligence, anti-gravity mech armor, planetary engines, sublight colonial ships, stellar detonators, etc…

This novel is also known as Gu Daoist Master

Humans are clever in tens of thousands of ways, Gu are the true refined essences of Heaven and Earth.

The Three Temples are unrighteous, the demon is reborn.

Former days are but an old dream, an identical name is made anew.

A story of a time traveler who keeps on being reborn.

A unique world that grows, cultivates, and uses Gu.

The Spring and Autumn Cicada, the Venomous Moonlight Gu, the Wine Insect, All-Encompassing Golden Light Insect, Slender Black Hair Gu, Gu of Hope…

And a great demon of the world that does exactly as his heart pleases!

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*Gu (蛊) referred to poisonous insects in various cultures in South China while in folklore Gu spirits could transform into all kinds of species.

- Description from Novelupdates

Tsubasa gets a second chance, reincarnated in the Naruto world.However, fate throws him into the Sengoku era, a time of relentless conflict.His sole advantage? A one-time cheat to create a ninjutsu. 'Venom' is his creation, his hope.Can this single ninjutsu ensure his survival and perhaps, something more, in this savage age?