Rurouni Kenshin - False Prophet, Vol. 4
Having escaped from Kanryu's deadly opium cartel, Megumi has become a trusted country doctor.  But the spiritualist Lord Raikou has other ideas, and the firepower to back them up.  He is a powerful faith healer who believes in magic over medicine, and he won't rest until Megumi is disgraced, discredited, or dead.