I Have a Mansion in the Post-apocalyptic World (Web Novel) - Chapter 1568: Reciprocity

Caught up in a ritual performed by a deity of another world, Eiji Choukai was then transported to another realm. The otherworldly deity responsible of the ritual looked at Eiji’s potential incarnations and quickly pulled out Classes like those from, “I Reincarnated Into a Vending Machine.”

But it seems the Classes available for the average person was not available to him. Only the “Parasite” Class was shown.

Without choice, Eiji grudgingly choose the Parasite Class.

His reincarnation into this new world seemed somewhat despondent, but after using his newfound powers, he suddenly realizes its true potential. It seems he’s able to amplify himself countless times by obtaining the powers of others. This luck of his was too good to be true. Seems his level might rise a little bit too much.

Good news: I have transmigrated to Teyvat and become the Heavenly Principle.Bad news: The world of Teyvat doesn’t have much time left.Good news: I have a system that allows me to devour two-dimensional worlds.Noah looked at the countless familiar worlds, tears of sorrow streaming down his face, and announced on the spot:“I will not only be the Heavenly Principle of Teyvat but also the Heavenly Principle of countless worlds.”“So, my rules are the laws.”From then on, one Heavenly Principle and a group of fierce Gods embraced trembling worlds one after another.After devouring the world of Demon Slayer, Teyvat’s lifespan increased by 5,000 years.After devouring the world of Akame ga Kill!, Teyvat’s barriers were strengthened by 100 times.After devouring the world of Inuyasha, Teyvat forms the cycle of reincarnation.…

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

At the age of 12, Naruto Uzumaki gained the extraordinary ability to traverse between his home world, the Ninja World, and the mysterious world known as the Soul Society.Naruto's DiaryKonoha Year 63, March 15: I seem to have died [crossed out] I seem to have died and come back to life.Konoha Year 63, March 16: The weight of this new existence crushes him. A return to life offers no solace, and he questions whether it might have been better to remain dead.Konoha Year 63, April 1: Desperation sets in as Naruto searches the Soul Society for his parents, only to discover that this world is not connected to his own. His parents are nowhere to be found.Konoha Year 63, July: The dream of becoming Hokage fades, as Naruto finds himself detached from the village that once held his heart. The desire to become a Shinigami grows stronger within him, spurred by the hope of discovering the true Soul Society of his world and reuniting with his parents.