Voidcutter
Weapon (longsword), Legendary (requires attunement)
This long, sleek sword isn't just black. No, the air warps around it and it seems to absorb completely any light that touches its blade, giving off no light at all. It feels like extremely cold metal to the touch, and yet when this blade cuts someone, their blood is pulled into it and disappears. When it cuts off a limb or digit, that is absorbed too. Anything absorbed by this blade is gone forever.
When you attune to this sword, choose between Intelligence, Wisdom or Charisma. The ability score you choose is your spellcasting ability for any spell you gain through being attuned to the sword and determines the DC for saving throws you force creatures to make using the sword.
Void blade. Whenever Voidcutter reduces a creature to an amount of hitpoints equal to or less than three times your level with a weapon attack, that creature must make a Constitution saving throw with a DC of 8 + your Proficiency Bonus + the ability modifier you chose when you attuned to this blade. On a failure, that creature is killed instantly and its body and any clothing it is wearing are sucked into the blade. All the rest of its equipment, including its weapons and armor, fall to the ground. If the blade reduces a creature to 0 hitpoints, this happens automatically. When Voidcutter absorbs a creature this way, it gains a number of Void charges equal to that creature's CR (rounded down). The blade can have a maximum number of void charges at the same time equal to your Proficiency Bonus.
Force strike. Whenever you hit a creature with a weapon attack with this weapon, you can expend any number of Void charges. If you do, the attack deals an additional 1d8 force damage for each expended charge.
Gravity magic. As long as you are attuned to this sword you know the Darkness spell, and while holding this weapon you can cast this spell by expending two Void charges without expending a spell slot or material components. If the sword is awakened or exalted, you also know the Gravity Sinkhole spell, and while holding this weapon you can cast this spell by expending four Void charges without expending a spell slot or material components. If the sword is exalted, you also know the Gravity Fissure spell, and while holding this weapon you can cast this spell by expending six Void charges without expending a spell slot or material components.
Expanding Weapon. This weapon is either dormant, awakened or exalted. Using it can cause it to change state, to expand and become more deadly.
Dormant. As long as Voidcutter is dormant, it is a +1 weapon, and it deals an additional 1d4 force damage on a hit.
Awakened. When Voidcutter reaches an awakened state, it becomes a +2 weapon, and it deals an additional 1d6 force damage on a hit instead of 1d4.
Exalted. When Voidcutter reaches an exalted state, it becomes a +3 weapon, and it deals an additional 1d8 force damage on a hit instead of 1d6. Additionally, the maximum number of Void charges the weapon can have at the same time doubles.
Art created using Midjourney AI