The Guardians' Throne - The First Magic Swordsman - Chapter 392 - Why?

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

Feng Ming was only 19 when he lost his life saving a child from death without hesitation. The grateful father of the rescued child grants Feng Ming a second chance at life. Unknown to Feng Ming, his soul has whisked away to a far away ancient land (resembling the dynasties of China).

Killed by a Sage Emperor and reborn as his 13 year old self, Nie Li was given a second chance at life. A second chance to change everything and save his loved ones and his beloved city. He shall once again battle with the Sage Emperor to avenge his death and those of his beloved . With the vast knowledge of hundred years of life he accumulated in his previous life, wielding the strongest demon spirits, he shall reach the pinnacle of Martial Arts.

One-eyed Wolf Lecan is a skilled adventurer who has conquered many dungeons all over the world. He had been going solo for a long time, but in the last three years, he’s had a partner. That partner jumps into the black hole together with Lecan, and both go their separate ways as they fall into another world. Dungeons and magical beasts also exist in that world. After learning the native language, Lecan goes on a journey. Meeting a good teacher, Lecan studies medicine making and magic under that teacher, and begins his dungeon explorations for real.