Scar

Though his real name and his past are unknown, Scar is a well-known killer in Central City, who targets State Alchemists due to his tortured history surrounding the Ishvalan Civil War.

Scar's right arm possesses the alchemical property of destruction.
This arm was given to him by his brother, after Scar lost his own to Solf J. Kimblee, who also gave him the "X" shaped scar from which he is given his name, during the Ishvalan Civil War.