Invincible! This person has lived for a billion years - Chapter 804 Top-level manager

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.

A detective travels across the United States and becomes an agent of the Los Angeles Police Department.

After getting through the initial confusion, he repeatedly solved strange cases, became famous all over the world, and was called the most legendary detective in history…

- Description from novelbuddy

One day, when a novelist woke up from a restless sleep,he realized that he had transformed into his 12-year-old self.

In a world ravaged by radiation and the remnants of war, Dylan is far from a classic hero. A lieutenant with a tainted past, he's just trying to survive the ruins of a dying world... until the day he wakes up bound and surrounded by the mutilated corpses of his comrades.Captured by monstrous creatures, he soon realizes he’s been transported to another world. A world far more dangerous, far more brutal—where only the strong survive, and even monsters are hunted. Saved in extremis by Maggie, his commanding officer, he begins a desperate escape. Their only hope may lie in their encounter with Élisa, an elf abandoned by her kin, and their discovery of a mysterious power: anima gems—stones imbued with spiritual essence that can enhance body and soul, and unlock the path to awakening.No One under 18 admitted