The Friends on the Other Side are responsible for giving Dr. Facilier his powers and aiding him in his schemes. They gave a voodoo necklace to Facilier to change Lawrence into Naveen, in order to inherit the LaBouff fortune by having Lawrence marry the sole heir of the fortune, Charlotte LaBouff. Facilier seems to be somewhat afraid of his "friends", because he owed a debt to them for giving him the magic he wants, which he is desperate to appease.
During the middle course of the film, Facilier made a deal to the "Head" Friend, that if they gave him shadow demons to help him in his plans that he would be able to give them all the souls of the New Orleans citizens to pay off his debt. Finding it fair enough, the Friends agree. Though the shadow demons manage to help out with Facilier's plans, the necklace was later taken and broken by Tiana. This leaves Facilier unable to pay back his debt, so the Friends turned on him, and claimed his soul along with his shadow to pay off his debt by dragging him to the Voodoo Underworld.