A black stone held up by a rusting chain. Upon wearing this necklace, the individual feels a sense of doom fall over them as the magic of the stone is activated. Any attempts to identify or detect the magic that the stone holds fail, giving whoever casted the spell a massive headache as well as 1 level of exhaustion. The only person who can know what the amulet does is the person who wears it, and they can't say exactly what the stone does to others, they'll only be met with pain and a voice telling them "SILENCE!"

This item is a cursed magical amulet that holds a dark entity with the confines of the stone. Anyone who wears this necklace is able to hear the voice of said entity and is also able to telepathically communicate with it. This amulet has its ups and downs for the wearer. The upsides are as follows: ALL attacks now deal an extra 1d6 Abyss damage*, you gain resistance to Abyss damage, and you can ask the entity any question, although it might not answer. The downsides to this amulet are what make it dangerous. First, the entity that is held by the stone can escape if the stone is broken (it takes 200 damage to destroy it and the damage resets after a full day has passed if the stone has not been broken). This entity has a CR of 20, so it's advisable to the wearer to protect the stone at all costs. Secondly, the wearer's life will slowly be drained after each full day has passed while wearing the amulet, the wearer's Max HP is reduced by 1 point every day. This effect cannot be countered by any means, except with the Wish spell. If the wearer's Max HP reaches 0 through this effect, and only this effect, then the stone is broken, the wearer dies instantly, and the entity is released. The wearer cannot be resurrected if they die by this way, as their soul has been consumed by the entity. This stone cannot be removed by any means except through the Wish spell, so it is advised that the party finds a high level Wizard that can use the Wish spell. It is up to the DM to determine how this can be done and what it'll take to get it done.

*Abyss damage is a homebrew type of damage for the campaign and world that I'm building for my friends and I. It doesn't have any special properties except for the fact that nothing can have a resistance to Abyss damage unless it comes from the Abyss itself. The Abyss, by the way, is the space that exists outside of time and space, between the boundaries of worlds, and cannot be accessed by anyone or anything, except for The Creator himself, Aeo. Again, another thing from my homebrew campaign and world.

Notes: Once this necklace is worn it attunes to the individual. This item does not take up an attunement slot if you play by those rules, and this item cannot be unattuned.