Barry the Chopper

Background
Barry was serial killer in Central, who murdered 23 humans. He was caught and taken for execution but he was offered a chance to live and guard the Laboratory 5.

Anime
Barry is first met when he kidnaps Winry and tries to kill her. Edward Elric rescues her and defeats Barry before he's going to kill them both. He appeares later in a suit of armour like Alphonse Elric in the Lab number 5. He plays with Al`s mind, making him think he is not real. Barry escapes from the Lab and begins to work with a mercenary, killing Ishballian people. He dies in hands of Scar, who destroys his blood seal.

Manga
Barry is first met in Lab 5 where he attacks Al. When Envy and Lust destroy the lab, Barry escapes. He is later met when he attacks Lieutnant Hawkeye in Central. Hawkeye shoots Barry and brings him to Colonel Mustang. Mustang makes deal with Barry and he's left to Falman's house. Sometime later, Barry frees Maria Ross from prison. Falman's house is then attacked by Barry own body and Homunculi Gluttony and Envy. Barry fights his body and follows it to Father's hideout. He is cut to pieces by Lust and later killed by his body.

Trivia
He seems to share a crush on Riza Hawkeye confirmed by the hearts around him, and him wanting to "chop" her up

He also seems to share a thing for Lust when he said that he wanted " to stick his cleaver in her" of course it could be a joke