Noir Wolf's past (a story of a Wolf Faunus )

This story is about a character I made up, her name is Noir Wolf, she is suppose to be a Dark Wolf Faunus who has a Dark and scary past. Noir and younger twin sister, Blanc Wolf who is a Arctic Wolf Faunus, are raised by their father Silver Eyes (who is a normal human being) after their mother Bianca (who was a Grey Wolf Faunus) dies. But when Noir and Blanc turned 10, something unexpected happens to Blanc.