One-man Army Gatse

Overview

After nuclear war broke out in the 1980s, a long nuclear winter descended on the Earth. Thirty years later, mankind has survived, but is engaged in an unending battle, even though the entire planet is in ruins. Arnold Gatse, the famous one-man army, is given a mission to defeat the enemy forever, by destroying the diglycidyl fortress at the heart of their base.

Source: AniList