Berserk of Gluttony (LN) - Volume 1 Chapter 2

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

At the end of the world, a legendary hero gave his life to save a dear friend, only to be reborn as a four-year-old orphan with 'Crab Affinity'.The apocalypse has come and gone, claiming humanity with it. All humans have had their 'Souls' stolen and claimed by monsters - vampires, demons, zombies - you name it.Reborn as Barnacles (Barns for short), the once-legendary hero claws his way back to strength under the tutelage of the gluttonous King Crab, a sentient crustacean with more vice than virtue in his shell.Follow Barns' journey as he rediscovers his power of rebirth, which when combined with a little 'crab magic' has the power to reset humans back to their original selves.It's time to take a crack at resetting the apocalypse.

One moment, Luo Jing was at the brink of death after accidentally touching a power outlet while showering. The next, he was in the body of a man named Garen, with memories of a past he was never a part of flowing into his head. As he slowly gets used to the body of Garen, he begins to explore a planet beyond his own logical comprehension. His journey will see him go from surviving in a planet locked in the 20th century, to wielding secret techniques so powerful that they level cities overnight. However, his journey doesn’t end with Garen. Instead this is but the first of many bodies that Luo Jing will come to wield in his mystical journey between worlds.