Fullmetal alchemist, vol. 8, paperback/hiromu arakawa

In an alchemical ritual gone wrong, Edward Alric lost his arm and his leg.

He was lucky.

his brother Alphonse lost his entire body.

With Alphonses soul grafted into a suit of armor, and the other brother equipped with mechanical limbs, they become government alchemists, serving the state on deadly missions and fighting the evil alchemists called the Seven Deadly Sins.