Naruto System in One Piece - Chapter 504: The Strength of the Four-Tailed

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

Grandpa Yu often repeated beside the ear of Yu Zhen, saying that he(YZ) has a soul in his body. If he doesn’t properly train in asceticism, and raise then send away the powerful soul, in this lifetime he would have to live as a bachelor. In his next lifetime he would be reborn as a lifestock animal.

Yu Zhen played on his mobile and nodded. On the surface he replied, “Uh-huh”. In his heart he laughed, “hahaha”. Keeping his grandfather in the dark was amusing so the lie was repeated for over ten years without Yu Zhen getting tired of it.

After some years, Grandpa Yu passed away and a cold-faced handsome guy came to his door in a luxury car – with a household register in his hands.

…..

Yu Zhen: The soul in my body reincarnated into someone else’s body to demand repayment, what should I do!

- Description from Novelupdates

After crossing over into a world of magic, Dean Bruce was mistaken for a powerful sorcerer. Though he initially intended to sternly refuse the beautiful woman’s request to become her mentor, she offered him far too much to say no!Completely clueless about magic, Dean Bruce had no choice but to make up spells on the spot. However, when he saw the astonishing power unleashed by the beautiful woman after chanting his random incantations, he was stunned.The spells he had carelessly invented… could they really comprehend magic and even forbidden spells?As Dean Bruce ascended to the pinnacle of magical prowess and became the Archmage, he candidly answered a reporter's question during an interview with the Alliance: “ never understood magic. I just made up a few incantations, that's all.”People were in awe of him—this, they believed, was the true humility of a Grand Archmage!

I had finally done it—achieved the ultimate Paladin build. Maxed stats, impenetrable armor, and so many resistances that death itself had given up on me. I was an unkillable tank, an indomitable force. Nothing could stop me.And then my PC exploded.I died.Irony, thou art a cruel mistress.But instead of the afterlife, I woke up as my Paladin character… in the wrong freaking genre. Instead of castles and dungeons, there were people flying around on swords, shooting qi beams like fantasy laser guns.“This is definitely the wrong genre,” I muttered, watching a pompous young master sneer at me.“Kowtow, kiss my foot, and beg for forgiveness!” he declared.I looked at my imaginary maxed-out health bar, then at his flimsy silk robes.Oh, this was going to be fun.