A dagger with a smooth obsidian handle and a curved, serrated edge made from a dark metal.

While unattuned, this weapon functions as a normal dagger. Upon attuning, 3 abyssal runes carved into the blade of the dagger reveal themselves. A number of runes equal to the number of charges in the weapon glow a faint red.

 

This weapon can hold 3 charges. Dealing the killing blow to a creatures with this weapon absorbs that creatures soul into the blade and restores a number of charges depending on the creature's Challenge Rating:

CR 1/4 - 4 =1 Charge

CR 5-8 = 2 Charges 

CR 9+ = 3 Charges

Once per round, a creature that hits with an attack with this blade can choose to expend 1-3 of the weapons charges, dealing an extra 2d8 necrotic damage per charge used and expending absorbed creatures' souls in a damaging blast. On a failed DC 12 Wisdom Saving Throw, the wielder takes the damage in addition to the attacked creatures.

Unattuning from the dagger requires a DC 18 Wisdom Saving Throw. On a fail, the attunement fails, and the dagger expends any unspent charges on the attuned creature and deals 2d8 necrotic damage per charge expended. The creature also immediately falls unconscious until the item is returned to their possession, or a Greater Restoration or Remove Curse spell is cast.

You have a +1 bonus to attack and damage rolls made with this magic weapon. 

Proficiency with daggers allow you to add your proficiency modifier to attack roles.

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

Notes: Bonus: Magic, Damage, Combat, Finesse, Light, Thrown, Nick