Naruto: I'm Nine-Tails and My Host is Kushina - Chapter 150

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

I am Master Siwei, and I speak for arcane arts.
This is an era of heroes and heroines.
This is an era of great changes.
In the end, it will be an arcane era opened by me.

- Description from Novelupdates

“I'll take this child.” Sold to the Wudang Sect's outer martial arts training hall for three silver coins at a young age, Kwak Yeon dreams of mastering supreme martial arts. But can he overcome the needle-sized gateway barely permitted to trainee instructors and rise to become a disciple of the main sect? “A true gentleman cannot stand idle in the face of injustice!” Thus begins Kwak Yeon's unyielding journey through the martial world, following the ruthless principle of “Kill Buddha, Kill Ancestors”—destroying all obstacles in his path!

This is a reincarnation/isekai story, about Matt (later TreeTree), an overpowered tree in a fantasy world that serves as the battlefield for an ongoing conflict between demons and the heroes summoned to oppose them.At first a bystander, over a long period of time, TreeTree will learn all sorts of skills, gain levels, and in doing so, build up a forest, train young subordinates, protect a village, and more.