Vecna's Blood Fury Tattoo

Produced by a special needle looted from Vecna's remains, this magic tattoo evokes fury in its form and colors.

Tattoo Attunement. To attune to this item, you hold the needle to your skin where you want the tattoo to appear, pressing the needle there throughout the attunement process. When the attunement is complete, the needle turns into the ink that becomes the tattoo, which appears on the skin.

If your attunement to the tattoo ends, the tattoo vanishes, and the needle reappears in your space.

Bloodthirsty Strikes. The tattoo has 10 charges, and it regains all expended charges daily at dawn. While this tattoo is on your skin, you gain the following benefits:

• When you hit a creature with a weapon attack, you can expend a charge to deal an extra 4d6 necrotic damage to the target, and you regain a number of hit points equal to the necrotic damage dealt.
• When a creature you can see damages you, you can expend a charge and use your reaction to make a melee attack against that creature, with advantage on your attack roll.

Cursed. Vecna's Blood Fury Tattoo is cursed, a fact that is revealed only when the Identify spell is cast on the needle or you attune to it. Attuning to the tattoo curses you until you are targeted by a Remove Curse spell or similar magic. Removing the curse ends your attunement. While cursed, you are unwilling to end your attunement to the tattoo or part with the needle.

While cursed, you experience the following effects:

• No Prisoners. Whenever you attempt to inflict non-lethal damage, you must succeed a WIS saving throw or do lethal damage instead.
• Bloody Overkill. Whenever you hit a creature with an attack roll and kill it, you must succeed a WIS saving throw or use your next attack to target the creature's corpse and tear it apart. You don't need to make a save if you cannot attack anymore on the current turn or if the creature left no corpse (like a Ghost). 
• Furious Retaliation. The first time in a round you take damage from a creature, roll a WIS saving throw. On a fail, your next attack or action during this round must be used to damage that creature if you can see it.

Escalating DC. The DC of the aforementioned WIS saves starts at 0 and increases by 5 every time you consume a charge of Vecna's Blood Fury Tattoo. It resets to 0 when combat ends or if you are Incapacitated.

Notes: Damage: Necrotic