Fullmetal Alchemist 3: The Girl who Succeeds God

The setting is Valdolla, a large city completely surrounded by snow-capped mountains.Edward, Alphonse, and Winry meet Sophie Belkman, a fourteen-year-old girl with silver hair and light blue eyes who has been cornered by Leonid, the guardian of ice. When Edward's attempt to save her from him fails, she uses a strange power causing a blinding golden light to light up the entire sky. (FMA Wiki)