Nightbane is an impossibly light greatsword with a sapphire pommel, platinum hilt, and crystalline blade. It is surprisingly heavy when sheathed.

Magic Weapon. This magic greatsword has the finesse property. If you are proficient with shortswords, longswords or greatsword, you are proficient with Nightbane.

You gain a +2 bonus to attack and damage rolls made with this weapon.

When you damage a creature with Nightbane, the target takes an extra 1d8 radiant damage or 2d8 radiant damage if the target is undead.

Wielder of Nightbane. While attuned to the sword, you gain the following benefits:

Healing Crystal. The sword has 4 charges and regains 1d4 expended charges daily at dawn. When you damage a creature with Nightbane, you can expend 1 charge to regain a number of hit points equal to the radiant damage dealt.

Sun blade. When drawn, and at the start of your turn, the sword chooses if it will:

• Burst. Emit bright sunlight in a 40-foot radius and dim light for an additional 40 feet.
• Gleam. Emit bright sunlight in a 5-foot radius and dim light for an additional 5 feet.
• Veil. Conceal its inner-radiance.

Dancing Sword. You can take an Action and/or Bonus Action to toss Nightbane into the air. When you do so, the sword begins to hover, flies up to 40 feet, and attacks one creature of your choice within 5 feet of itself. The sword uses your class features, feats, attack rolls and adds your ability modifier to damage rolls, if you have the Extra Attack feature you may choose more than one creature to attack with your Action. 

While Nightbane hovers, you can take an Action and/or Bonus Action to cause it to fly up to 40 feet to another spot within 40 feet of you. As part of the same Action and/or Bonus Action, you can cause the sword to attack or cast a spell as though you were holding it in it’s space, but you must use your own senses.

After the hovering sword attacks for the fourth time, it flies back to you and tries to return to your hand. If you have no hand free, Nightbane falls to the ground in your space. If the sword has no unobstructed path to you, it moves as close to you as it can and then falls to the ground. It also ceases to hover if you grasp it, another creature uses its action to grasp the hilt with a successful DC 18 Dexterity (Acrobatics or Athletics) check or you are more than 40 feet away from it.

Additional Properties. The sword has the following additional properties:

• While attuned to the Artefact, your Strength ability score increases by 2, to a maximum of 24.
• While attuned to the Artefact, your Dexterity ability score increases by 2, to a maximum of 24.
• The first time you become attuned to the Artefact, it gives you a quest determined by the DM. You can’t use any of the Artefact’s properties until you complete the quest.

Sentience. Nightbane is a sentient chaotic good weapon with an Intelligence of 9, a Wisdom of 17, and a Charisma of 16. It has hearing and darkvision out to a range of 60 feet. The weapon can speak and understand Common and Celestial, it communicates telepathically to the creature carrying or wielding it, and any other creatures it chooses within 60 feet. 

Personality. The sword is usually cheerful, eager to help, and craves approval, but it is self-centered and it does not like to be ignored. Nightbane one purpose: To destroy evil. It is not bloodthirsty, it just wants to be useful… but it does need your help to understand what evil is.

Curse. Creatures with an evil alignment see the sword as desirable.

If any creature grasps Nightbane’s hilt, the sword may then choose to use the Dancing Sword feature (as if tossed by you) but without expending your Action and/or Bonus Action and controlled by the DM. If the sword is sheathed or held and the creature is unwilling they must make a DC 18 Strength Saving Throw to prevent this and keep hold of the sword.

Nightbane can continue hovering and attacking this way (as per the Dancing Sword feature but without expending your Action and/or Bonus Action) except all references to 40 feet refer to the creature who grasped the hilt, instead of you. Whilst hovering this way, when the sword deals damage it can choose to expend a charge to heal you (Healing Cystal feature).

Sheathing the sword always requires an action and a successful DC 18 Strength (Acrobatics or Athletics) check, unless it has fallen to the ground from ceasing to hover. However, if any creature grasp it’s hilt, the sword can choose to hover again.

If the sword is still unsheathed at the end of your turn, the last creature to grasp the hilt is drained of one hit die unless Nightbane was used to deal damage on your turn or the creatures. If the creature has no hit dice remaining its hit point maximum is reduced by 16. This reduction lasts until the creature finishes a Long Rest. The creature dies if this effect reduces its hit point maximum to 0.

Destroying the Sword. Nightbane can only be destroyed if you convince the sword that it is evil and must destroy itself.

Proficiency with a Greatsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Radiant, Weapon Property: Finesse, Damage: Radiant, Bonus: Strength Score, Bonus: Dexterity Score, good or neutral creature, Healing, Damage, Combat, Cursed, Heavy, Two-Handed, Graze