Amulet of the Life Drinker

A small skull, roughly carved from black stone, dangles from a jagged black steel chain. The skull’s eyes flicker with eerie green flame, and evil looking markings are etched into its surface. A creature that spends a Study action to examine the amulet and succeeds on a DC 20 Arcana or Religion check recognizes the markings as inscriptions in Abyssal, whispering of the endless hunger of the infinite void.

Life Drinker. While attuned to this amulet, you have resistance to Necrotic damage. When you hit a creature (excluding constructs and undead) with a melee weapon attack, you regain hit points equal to half the damage dealt. Additionally, the target's maximum hit points are reduced by an amount equal to the hit points you regain. This reduction lasts until the target finishes a long rest. A creature whose maximum hit points are reduced to 0 by this effect can only be resurrected by true resurrection or wish. Each time you hit a creature with a melee weapon attack, both your and the amulet's eyes flare with green flame as the creature's life essence is absorbed into you through the amulet

Curse. The amulet is cursed and attuning to it extends that curse to you until you're targeted by a greater restoration spell or similar, more powerful magic. Once attuned, you cannot willingly unattune from the amulet. Removing the necklace does not end the curse. Being separated from the amulet causes it to burn with malevolent power, dealing 8d6 necrotic damage to you and any creature who attempts to or does remove it. If the amulet stays removed, you suffer 1 point of exhaustion ever hour until you die and suffer the following effects.

Call of the Abyss.
If you drop to 0 hit points while wearing the amulet, your soul is instantly consumed by the Abyss and the amulet disappears, fading into smoke and ash, no longer providing any benefit to you. Your body rises at the start of your next turn as a powerful wight, now an empty vessel of hunger and death. If and when your body is destroyed, it fades into ash and smoke just as the amulet did. Only true resurrection or wish can restore your soul once claimed by the Abyss.

• Your transformed body immediately seeks out and attacks the nearest living creature, showing no regard for former allies or loyalties. It fights relentlessly until it is destroyed. 
• Your body retains all class features, racial traits, and abilities it had in life, but it is now considered undead.
• Your maximum hit points become half of what they were in life.
• You drop anything you were holding, and your hands transform into necrotic enhanced claws, replacing any previous unarmed strikes. You gain a Multiattack action, allowing you to make four claw attacks.
• Your attack modifier for your claw attack is STR or DEX (whichever is higher) + PB. 
• Your damage modifier for your claw attack is 1d8 + STR or DEX (whichever is higher) + 2d8 Necrotic damage.
• Your speed increases by 10 feet, and you can move half your speed as a bonus action without provoking opportunity attacks.

I was out of options. My people needed an edge in the war for our survival, and what the shaman offered me was worth the price. I know that dark magic fuels this amulet, but if it is what gives me the power to save my people so be it. My soul is a small price to pay and I will bear the burden proudly. I can only pray that when I fall, it is amongst enemies, and not allies.

Notes: Resistance: Necrotic, Healing, Debuff, Utility, Combat, Cursed, Necklace, Jewelry