In JJK With Naruto Powers - Chapter 13: Surprise

Felix Ariel, a typical Floridian, found himself transported to a mysterious kingdom in another world. However, a misunderstanding led to Felix accidentally killing the king, resulting in his untimely demise.Following this tragic event, Felix's spirit encountered a mysterious being who identified as Felix's ancestor. This entity claimed that Felix had been cursed by an unknown individual. For Felix's safety, the ancestor bestowed upon him a system for self-defense.Upon returning to Earth, Felix realized that he would be transmigrated to the alternate world at noon due to the lingering curse. To prepare for this unexpected transmigration, Felix relied on the system, which required him to gather oil and gold to enhance his abilities.Thus began Felix's quest in the other world. With his system, he brought firearms and an ambition to spread liberty... for prosperity and freedom.

The Immortal Dao is ethereal, and Immortals are hard to find.

Li Nianfan had descended into the cultivation world as a mortal. After learning that he has no hope in cultivation, he only wants to live a peaceful life.

However…

The dog he adopts becomes a demon king of a generation when it sees his poems and paintings. It manages to suppress an entire world.

The tree he plants behind his house becomes a World Tree after listening to his zither music, forming a bridge between heaven and earth.

He meets a passerby who is enlightened by him and becomes an immortal sage who leads an entire generation.

When he looks back—

It turns out that the scholar who had been pestering him for his calligraphy and paintings despite having crappy chess skills, is a chess saint from the Immortal Realm. The beautiful woman who comes to listen to his music every night is the number one saintess of the Immortal Realm…

The reborn Prince Hechingen of the Swabian branch of the Hohenzollern family, sees the situation in Europe, and the war is about to start, so Europe doesn’t wait. Enclosure in East Africa, immigration development, and agricultural foundation, step by step, with the help of the crisis to achieve industrialization.

- Description from novelbuddy