The Guidebook for Villainesses - Chapter 17

Reborn in the world of Naruto as the Nine Tails, he finds himself sealed within Uzumaki Kushina. No longer just a mindless beast, he possesses his own will, intelligence, and the power to change the fate of the tailed beasts.Madara : I never thought that my Rinnegan would be crushed by Nine Tails.Hashirama: Times have changed. I once controlled the Nine Tails, and now the Nine Tails controls me.Uchiha Mikoto: Kushina, I didn’t expect you to have something this powerful sealed inside you.Uzumaki Kushina: Each of the Nine Tails' tails gives me a different feeling.At this moment, the Nine Tails stood tall, representing all the tailed beasts.“Tailed beasts will never be slaves!”

A serious accident caused the protagonist’s brain to have an unusual mutation. This changed the brain development that it opened the door to a mysterious universe. Not only he obtained a ‘god-like’ powerful telekinetic control and mental perception, he also had an abnormal analysis and memory capability comparable to super computer. Having such super brain, his rough life began.

Brain development progress 10%…….20%……50%….80%…. …100%

- Description from Novelupdates

In a world where magic was abundant and supernatural creatures existed, Jin Valter lived as a fallen genius. Being the son of two A-Ranked Hunters, Jin had inherited his father’s keen eye for martial arts and his mother’s innate talent for magic. Alas, before Jin could reach his full potential, an Outer Demon attack left his soul crippled and his body weakened beyond repair.

Now, Jin lives out his days bound to the hospital bed with nothing but his brains to keep him company. Gone were the days when his peers hailed him as a genius as he struggled to even conjure a spell with his body falling apart.

However, it would all change when on the Night of the Blood Moon, a unique visitor paid him a visit…

Thrown into his favorite novel as a powerless extra, he never expected to survive, let alone tame the gods.In a world where strength is everything, chaos reigns and beasts roam the land, including fearsome dragons and gods, the stakes have never been higher.With the power to tame beasts that even gods fear, he must rise above a world on the brink of collapseBut how will he fight for his place in a doomed reality!