root-book

Two years ago, the world was shattered by a monstrous invasion through dimensional rifts. Derukan, a fallen military trainee, awakens in another dimension with the ability to regenerate and a mysterious, living mechanical arm created by interdimensional scientists. Though ranked as F-class, he hides an SSSS-class power system and begins his mission to save his sister, uncover the truth of the red sky, and reshape the fate of all dimensions.