Seiju no Kuni no Kinju Tsukai
(https://i.imgur.com/JyuQKm1.jpg)
Original Title: 聖樹の国の禁呪使い
Alternative Title: The Forbidden Spellcaster of the Sacred Tree Kingdom
Author: Shinozaki Kaoru (篠崎芳)
Illustrator: Shimesaba Kohada (〆鯖コハダ)
Publisher: Overlap Bunko
Failed on his job-hunting, shut-in Sagara Kurohiko went to the mountain on the day of a typhoon where he is struck by lightning and dies. But he is still alive, in a strange land with a great holy tree. To his surprise, his physique has rejuvenated to when he was teen. Brought to the academy near the tree, he is soon suspected as a spy from another country, and was brought to the headmaster. An accident happened on the way, which enraged the headmaster. Before Kurohiko can get blasted by magic, his eyes laid upon an old parchment. He took it and read the contents. Suddenly four holes appeared and black chains came out from each of it, binding the headmaster. It is then revealed that Kurohiko just recited an incantation of "Forbidden Art," an art which is extremely powerful from a legend. Apparently, no one has been able to decipher the contents of the scroll, which makes Kurohiko the only current Forbidden Spellcaster. Sparked by this, the headmaster offers Kurohiko to attend the academy.
Download:
Vol 1 http://sh.st/O8edO
This is more like chapter 1 or so, not nearly long enough to be volume 1
U have a point. It's really too short to be light novel , but then this is how i got the file form somewhere else, it was like this. I'll try and search for a different version if available then share it.
So i dont think this is the LN, but here it is, :D
hopes it is or at least the ones who looks for it can read it :D
https://www.hasutsuki.com/p/blog-page_18.html
up to chapter 70 :D