Start With Contracting Sprites - Chapter 621 - The bear that triggered the lightning tribulation (2 in 1)

Nagasawa crossed to Naruto Universe and was bound to Konohagakure.If Konoha is severely damaged and destroyed, Nagasawa’s lifespan will be reduced.He panicked at the thought of the upcoming Nine-Tailed Demon Fox's attack , and the thought of Konoha getting destroyed left him in despair.Fortunately, while bound to Konoha, he can obtain templates of powerful characters.At the beginning, He got the Whitebeard template! Since it's the Whitebeard from the Summit War of Marineford, he can use Tremor-Tremor Fruit's ability and Haki.Facing the Tailed Beast Ball, which terrorized Konoha Shinobi, Nagasawa leaped and shattered the Tailed Beast Ball with one punch!

When I became a rich young master, I had to enjoy it.
Training? No!
That is so boring.
I have a system, no need for training.

Are you hungry? Come, I will treat you with some food at a luxurious restaurant.
What a poor homeless. Come, I will give you a house.

I, Lin Fan is a good person.

- Description from Novelupdates

Lin En transmigrated into a magical world that resembled medieval Europe but had the power of magic.Here, magic could affect and control basic particles, which was based on scientific theories that served as magic formulas!The wizards, who were actually scientists, were struggling to explore the truth of the world under the chase and blockade of the church. Lin En’s arrival sparked a renaissance of the alternate world…The white phosphorus fire, known as the Flame of Hell, the liquid nitrogen field of extreme cold, and the resonance frequency that kills without a trace… A few years later, the Holy See gathered all countries to the city, known as the legendary wizard, the pioneer of magic Lynn under the gaze of a group of wizards, wrote down the mass energy equation known as the ladder of God by later generations! Lynn looked around the crowd and said nonchalantly. “Mass and energy are interchangeable, and based on this theory, I have developed a powerful forbidden curse… It’s called — “The Big Nuke!”We will re-examine the world from the perspective of magic, where science is magic, and magic is science!

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.