A diviner or a shaman.
1) A diviner also an herbalist, divines with charcoal, ginger, and other talismans; invokes a familiar spirit to assist in diagnosis, but does not require or know how to elicit any further action by the spirit. Diagnosis involves identifying the agent/cause of a sickness (usually the fattest pig of the family which is then sacrificed as treatment, and the diviner receives first choice of the meat). He may also administer various herbs and/or concoctions. 2) The shaman invokes the same familiar spirit to punish or avenge a sick person by an offering to the spirits ātang. Vinegar is the main ingredient used to determine the cause of a sickness or curse.