ファントム バレット

A gunslinger kills a man and states "Whenever humans try to attain more power using this book, a gunslinger will appear for them."

Fifteen years later, in a Polish village, a young girl sees her mother killed just in front of her by Nazi soldiers during WWII.
The girl then decides to use the book to take revenge on her mother's killers despite the threat of the legendary gunslinger who kills all those who misuse the book.