Planet Pulverizer: A Mortal's Ascent - Chapter 4: Astral God

A young man playing games in his basement is struck by a mysterious bolt of lightning, killing him instantly. However, he wakes up in the body of a disgraced young lord, now tasked with managing a ruined, crumbling kingdom. With no experience and a tarnished reputation to overcome, his future seems bleak.Fortunately, he possessed the Omnishop System, a mysterious tool that enabled him to purchase skills and supplies as well as upgrade his existing skills using points. Rebuilding the kingdom is no easy feat, but Alexander has his sights set on more than just survival.With ambition burning in his heart, he dreams of ruling an empire, if he can survive the challenges ahead.

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

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.