Sekigan, Sekiwan, Sekkyaku no Majutsushi @Comic: Mori no Koya ni Komotteitara Haya 2000-Nen. Kizukeba Majin to Yobareteita. Boku wa Tada Majutsu no Tankyuu wo Shitai Dake nanoni

Overview

As a young boy, Ains tragically witnessed his village being burnt to the ground by enemy forces. By the time rescue arrived, he lost his right arm, left leg, and right eye. Despite such misfortune, his only concern was the magic he saw for the first time among the debris. In order to study it, he withdrew from society and secluded himself in a cabin in the woods for two thousand years. When he finally emerges as an all-powerful mage, his childhood village has transformed into a sprawling city. But that's not all! The scribbled notes he left behind have become the “Original Scripture,” and he's infamously known as the “Demon God.” Can Ains find his place in the world after millennia have passed? (Source: Seven Seas Entertainment)

Source: AniList