Chrono Crusade Vol 5

Chrono Crusade Vol 5 by Daisuke Moriyama. An Action manga rated Teen, published in English by ADV in 2003.

In 1920s America, Sister Rosette Christopher, a hot-headed nun, and her partner Chrono, a demon who has sealed most of his power, work for an order of exorcists. They hunt demons while searching for Rosette's missing brother.