Envy (FMA 2003)

Envy’s manga and 2009 anime counterpart was pitiful. The 2003 anime version, however, is a malevolent sadist who gets his fun out of ruining people's lives.

He crosses the Moral Event Horizon with Hughes' murder and then follows it up with a string of murders and mind games that end with his killing Ed. He's got a stroy of being anbandoned as a Freudian Excuse, but it doesn't come close to justifying his homicidal mania, and he ultimately undermines it when he kills his father rather than trying to reconnect with him.

History
In the 2003 anime series, Envy is the first Homunculus created. As in this (radically different) storyline homunculi are created after a human transmutation, which only produce and alchemic "clone" of the deceased one, he was created 400 years before the beginning of the series by Dante (this storyline's main villain) and Hohenheim, in an effort to revive their late son who died of mercury poisoning. Envy holds a staunch grudge against Hohenheim (who abandoned him and Dante after realising that their son would never truly return) for not recognizing him as a son. He is also extremely jealous of the protagonists of the series, Edward and Alphonse Elric the sons of Hohenheim (for receiving the parental love that he never got). His hatred is so strong that he never assumes his true form (which looks a lot like Hohenheim and the Elrics) pretending to have forgotten it. He harbours a fierce hatred for humans, wanting to kill as many of them as possible, and would stop at nothing to kill his "father" and "brothers".

Envy remains by Dante's side all along, carrying her dirty work for the sole pleasure of seeing humans die and suffer. After his final battle against Edward Elric in which he reveals his true face to distract Edward and severely wounds him, he transforms into a huge snake-like dragon and goes beyond the Gate of Truth into the real world, where Hohenheim has been banished.

During the two year gap between the end of the anime and Conqueror of Shamballa, Envy was captured by the Thule Society. With Envy in his massive serpent form, the Society intended to use him as a literal Ouroboros to open a physical Gate and transfer their soldiers to the other side, to "Shamballa". Hohenheim was imprisoned and offered to Envy as a sacrifice; a human chew-toy to keep the "Great Serpent" calm as they formulated their plans. Around the time of Fullmetal Alchemist the Movie: Conqueror of Shamballa, Envy escaped and took shelter in an abandoned castle, only to cross paths with Edward once again.

In their ensuing fight, Envy was attacked on all sides by the Thule Society, who recaptured him and managed to get a small regiment of soldiers to the other side for a short time. In the end, it was Hohenheim who took his own life using Envy as his means, enabling Ed to return to his own world in a final act of redemption for his sins, using him as material to create a gate between the two worlds. Thus, Envy finally realized his sole desire to kill his father, ultimately at the cost of his own life. He was the seventh and final Homunculus to die in the series. It is not known whether or not Envy forgave Hohenheim before his death, though it is not likely.