Amulet of Vistana

This amulet is made of hellish steel, gold and streaked with veins of hellfire that emit a dim light in a 5 foot radius when activated, while tuned its eyes change to blood red. While in possession of such amulet, you have access to the following attributes:

Infernal Majesty: Your Charisma score increases by 2, up to a maximum of 22. 
- If you are not wearing armor, your base Armor Class is 15 + your Charisma modifier. 
- You are under effec of one option of the thaumaturgy trick while using these amulet, can changing by another one with a bonus action.

Baator Protection: While in your possession you have immunity to fire damage, energy, and this amulet provent you ability as you was at effect of Freedom of movement.

Best friend of the warlock: You mastered your arcane powers from your pact you add a +2 in you attack rolls and DC for spells, you can add 1 adicional option for your mystic arcanum options, extend 2 more weapons for your pact weapon and 2 more eldritch invocations indepedent of your pact option.

Bestower of curses (3 charges, Recharges After a Long Rest): While attuned whit this amulet, you can use an action to utter a curse targets one creature that it can see within 30 feet of it. The target must succeed on a Wisdom saving throw, the DC is 8 + your profiency bonus + your charisma modifier or be cursed. The User chooses the curse's effect from the options that follow; other Vistani curses are possible as the DM allow it. All such effects deal psychic damage to the User who uttered them when they end.
The curse lasts until ended with a greater restoration spell, a remove curse spell, or similar magic. It doesn't end when the target dies. If a cursed target is returned to life, the curse remains in effect:

• The target is unable to perform a certain kind of act involving fine motor control, such as tying knots, writing, playing an instrument, sewing, or casting spells that have somatic components. When this curse ends, the User takes 1d6 psychic damage.
• The target's appearance changes in a sinister yet purely cosmetic way. For example, the curse can place a scar on the target's face, turn the target's teeth into yellow fangs, or give the target bad breath. When this curse ends, the User it takes 1d6 psychic damage.
• A nonmagical item in the target's possession (chosen by the DM) disappears and can't be found until the curse ends. The lost item can weigh no more than 1 pound. When this curse ends, the User takes 1d6 psychic damage.
• The target gains vulnerability to a damage type of the User's choice. When this curse ends, the User takes 3d6 psychic damage.
• The target has disadvantage on ability checks and saving throws tied to one ability score of the User's choice. When this curse ends, the User takes 3d6 psychic damage.
• The target's attunement to one magic item (chosen by the DM) ends, and the target can't attune to the chosen item until the curse ends. When this curse ends, the User takes 5d6 psychic damage.
• The target is blinded, deafened or both. When this curse ends, the User takes 5d6 psychic damage.

Curse: This amulet is cursed and imbued with infernal energies, when you tune in to it, the curse extends to you. You can only tear apart with the amulet by a wish spell or removed by the hands of an achdevil. After 1d6 days of attunement, the user will begin to suffer some changes caused by the amulet. The user will become attached to the amulet, refusing to take it of or let others touch it. 

Detrimental properties: 

You will also slowly lose any empathy for others, caring for only 5 creatures of your choice, it will treat any other creature with sadistic emotions, not caring about their lifes, acting unpretentiously to them. The users skin will slowly turn pale red and feel hot to the touch. Their hair and irises wine red with vestigial deer horns.

Each time you deal fire damage, you must succeed on a DC 12 Wisdom saving throw or accidentally summon a hostile barbed devil (depending on the damage dealt).

Wring Out. Whenever you waste a charge while attuned to the Amulet, it shows their powers to the universe when, are in the presence (a sphere of a 20 foot raius sphere) of other legendary items there is a 10 percent chance that you attract the attention of a god that sends an avatar at some time to wrest the item from you and other one that he consider dangerous for his god. The avatar has the same alignment as its creator and the statistics of an empyream (see the Monster Manual). Once it obtains the artifact, the avatar vanishes.

Celestials are always hostile toward you.

Notes: to a being who has made a pact with a devil