Witchlight Vane

From The Wild Beyond the Witchlight, page 27.

Description
Wondrous item, legendary (requires attunement by Mister Light or his handpicked successor)

This ornate rod is topped by a pair of butterfly wings and incorporates bits of red glass into its length. It weighs 3 pounds.

Magic Weapon. In the hands of one who is attuned to it, the vane can be wielded as a magic mace that grants a +3 bonus to attack and damage rolls made with it. In addition, the vane deals an extra 1d8 radiant damage on a hit.

Sense Mood. While the vane is inside the perimeter of the Witchlight Carnival, it can sense the mood of every creature in the carnival that has an Intelligence of 4 or higher. As an action, a creature attuned to the vane can use it to pinpoint the location of the happiest creature in the carnival. The butterfly shape at the top of the vane spins slowly clockwise when spirits in the carnival are generally high; if the general mood in the carnival is dour, the top of the vane spins slowly counterclockwise.

Sentience. The vane is a sentient, chaotic good wondrous item with an Intelligence of 11, a Wisdom of 14, and a Charisma of 14. It has hearing and normal vision out to a range of 30 feet, and it communicates by transmitting emotion to the creature attuned to it. Its purpose is to make sure everyone in the Witchlight Carnival is having a good time.

Additional Properties. The vane has the following additional properties:
 * The creature holding the vane has vulnerability to lightning damage.
 * The creature attuned to the vane can't be blinded, deafened, petrified, stunned.
 * While carrying the vane, the creature attuned to it can cast the Dancing Lights, Polymorph, or Ray of Frost spell as an action, requiring no spell components and using Charisma the spellcasting ability. After the vane's Polymorph spell is cast, roll a d8; on a roll of 3 or 8, the vane can't be used to cast this spell again until the next dawn.