Star Odyssey - Chapter 22: Bloodlust Under Moonlight

A mysterious teenager who had lost his past, awakened in Tianlong Continent. Mistaken as the Ye family’s Son, he used this identity to observe this chaotic world and to search for his past self, but only to find an inevitable and terrible fate, therefore he indignantly laughed at his destiny, and revealed his prowess to rule the lands under the heavens.

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

Wu Lai was an ordinary high school student. One day he was struck by a flash of lightning from a different world, and suddenly entered a fantastic world full of magic and swords. Since then, he started a totally new life. In this supernatural world, he had his ups and downs, experienced numerous battles, subdued powerful evil beasts, and fell in love with a belle. His nickname “Demon King” was remembered throughout the ages there.

Stay or return was a question. In the face of this choice, Wu Lai, with the nostalgia and gratefulness for the original world, finally chose to stay…

Here was the legend of “Demon King”…

- Description from Novelupdates