Fullmetal Alchemist, Vol. 7 — Hiromu Arakawa

In an alchemical ritual gone wrong, Edward Elric lost his arm and his leg, and his brother Alphonse became nothing but a soul in a suit of armor. Equipped with mechanical "auto-mail" limbs, Edward becomes a state alchemist, seeking the one thing that can restore his brother and himself...the legendary Philosopher's Stone.
Where did Alphonse Elric go during the few short minutes he was wiped from existence, body and soul? From a secret lair in the city of Dublith, a group of outcasts kidnaps Alphonse to find the alchemical secrets of his creation! It's up to Ed (and a certain housewife) to go into the Devil's Nest and rescue his brother. But the criminals of the Devil's Nest aren't exactly human either. Now, Al must fight a homunculus -- an artificial human being -- and the streets of Dublith will run red with blood...