Wailing Belt
A string of shrunken head attached to a belt. Once per day, as a bonus action, the wearer can activate the heads, who will weep, scream, curse their fate, roll their eyes, prophesy doom on the wearers enemies, etc.
Any creature in a 20 foot radius must make a ____ saving throw or be frightened for X rounds. Out of combat, wearer has advantage on Intimidation checks, disadvantage on all Persuasion checks. Non-evil creatures will treat the wearer with a mixture of fear and disgust.
Edited to add a thought; if your characters don't want to wear the belt, it could be used as a plot hook to return one or all of the heads to their land of origin, put their souls at rest, etc.