Craven Edge (5e Equipment)
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Weapon (greatsword), legendary (requires attunement by a creature of non-good alignment)
This beautifully crafted onyx blade houses an intelligent, every hungry entity connected with its dark power. You gain a +2 bonus to attack and damage rolls made with this magic weapon. It has the following additional properties.
Dark Aura. When you wield Craven Edge unsheathed, you have advantage on Charisma (Intimidation) checks.
Devour the Weak. Whenever Craven Edge damages a living creature, that creature must roll a Constitution saving throw (DC 12). On a failed save, Craven Edge drains one point from the creature's Strength score and transfers it to the wielder (increasing to a maximum of 25 Strength) until the next short rest or long rest. Creatures brought to 0 Strength by this feature are slain.
Gluttonous Evolution. If Craven Edge devours enough strength from Devour the Weak to bring the wielder to 25 Strength, then the blade shifts form into a larger, jagged blade that seeps shadow. Until the wielder's next short rest or long rest, all attacks with this sword deal an additional 2d6 necrotic damage. After resting, the attuned creature must make a Constitution saving throw (DC 16) or have the now-hungry weapon, energy spent, devour the wielder's soul, killing them instantly.
It will bargain and promise but will not tolerate mockery or jest at its expense. If the wielder attempts to discard it in battle for another weapon, it may attempt to force its will to override that of its user. The wielder may need to succeed on a DC 16 Wisdom Saving Throw, or be unable to drop Craven Edge
Craven Edge may house the soul of a man, long forgotten, and cursed to never be satiated.