For this mission, a little training can be useful (e.g. getting Duvalier Feedback and the Blood Orb could come in handy). After talking to Griffin, head to the Marid Campgrounds and speak to the Chief Hamzah. You'll find him unwilling to help you fight the Cult, but if you suggest to root out a problem with the Bandits, then he'll provide you with a guide, who'll get your group to Bandit Territory. You'll face 4 battles.