My Wife is the Asura Empress - Chapter 331 Bound by the Slave Mark

Qin Tian accidentally transmigrated into a sickly body, a body with broken Dantian that was unable to practice Qigong, in another world. Fortunately, God had mercy on him by giving him a level up system. Useless? That was him in the past. Not worrying about practicing Qigong, he was now able to kill Monsters to level up. Easy! Level up when killing Monsters; level up when killing people. An unbeatable sovereign of the clan in the eyes of other people, but in his eyes, he is a glittering big BOSS.

“Honey, it’s time to take your medicine!”

The beautiful and pure saintess brought medicine to treat the wound.

On this day, he saw betrayal with his eyes, and experienced despair with his soul…

From this day on, the brave is dead, burn paper if something happens!

- Description from novelbuddy

There are three realms in the multi verse; The Cosmic, the Mortal and the Nether realm.

Hal grew up in the mortal realm with no idea whatsoever of who his parents were.

His love for relics, adventure and the occasional danger would aid him in finding a genie's lamp.

Rubbing a genie's lamp should grant three wishes, but Hal is struck by lightening instead and eventually arrives in the Cosmic realm with a large book in his mind space titled; The Primordial Cosmic Grimiore, that apparently holds all knowledge for a perpetual reign.

And so Hal's journey begins in a little city called Salmon city, in the body of a 17 year old boy also named Hal but was sold into slavery by his own father.

Hal finds out who his mother (prior to reincarnation) whose bloodline now flows unmixed in his new body is....

Join Hal as he battles mortals, Dragons, phoenixes, Gods and many more together with his harem of Beauties for the complete subjugation of the three realms.

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.