Moonflower

A magical flower created by the ArchFey Fen. It was designed to extend the life of the creature that regularly consumed it while also ensnaring them to Fen's command. This allowed Fen to creating a following that was more resilient and completely loyal to their deceitful master.
Once a person was under Fen's thrall he would communicate with them through dreams and whispers and guide them on how to cultivate more Moonflowers. Once the subject was sufficiently proficient they would be sent to a new town to enslave them.