Choker of Proof Against Detection and Location -- Cursed

This dark metal, thin, chain choker bears a sigil of a stylized dragon in flight. The type of dragon of the sigil is unclear. While wearing and being attuned to this item, you are hidden from divination magic. You can't be targeted by such magic or perceived through magical scrying sensors. However, this item has been cursed by a powerful fiend to provide the exact opposite effect for CrOFL of the Mercykillers. CrOFL, general of the mercykillers, can use this item as a focus to increase the range and scope of location and divination magics on you to any place in any plane of existence. When used in this way, the amulet feels warm to the touch.
You are unable to remove or unattune to the cursed item until the fiend that cursed the item releases the curse. Any other attempt to un-curse the item fails. A forced removal of the item from the wearer brings the wearer to zero hitpoints and disintegrates the wearer to dust with no saving throw or ability to avoid the effect.
The character learns of these properties when he first puts the choker on his neck as it immediately attunes to him unless he makes a DC 30 charisma saving throw.