A long forgotten experiment from the god of hidden knowledge, Abhorrence was an attempt to create a new weapon borne of demons. Deemed a failure it was never given the chance to grow.
You gain a +3 bonus to attack and damage rolls made with this magic weapon. It has the following additional properties.
Devour Soul
Whenever you use it to reduce a creature to 0 hit points, the sword slays the creature and devours its soul, unless it is a construct or an undead. A creature whose soul has been devoured by Abhorrence can be restored to life only by a wish spell.
When it devours a soul, Abhorrence grants you temporary hit points equal to a third of the slain creature’s hit point maximum. These hit points fade after 24 hours. As long as these temporary hit points last and you keep Abhorrence in hand, you have advantage on attack rolls, saving throws, and ability checks.
If you hit an undead with this weapon, you take 1d10 necrotic damage and the target regains 1d10 hit points. If this necrotic damage reduces you to 0 hit points, Abhorrence devours your soul.
Soul Hunter
While you hold the weapon, you are aware of the presence of Tiny or larger creatures within 60 feet of you that aren’t constructs or undead. You also can’t be charmed or frightened.
Abhorrence can cast the haste spell on you once per day. It decides when to cast the spell and maintains concentration on it so that you don’t have to.
Sentience
Abhorrence is a sentient chaotic neutral weapon with an Intelligence of 17, a Wisdom of 10, and a Charisma of 19. It has hearing and darkvision out to a range of 120 feet.
The weapon can speak, read, and understand Common, and can communicate with its wielder telepathically. Its voice is deep and echoing. While you are attuned to it, Abhorrence also understands every language you know.
Personality
Abhorrence speaks with an imperious tone, as though accustomed to being obeyed. While not impossible it has yet to find a master it agreed with, often consuming the soul of it's wielder before long.
The sword’s purpose is to consume souls. It doesn’t care whose souls it eats, including the wielder’s. The sword believes that all matter and energy sprang from a void of negative energy and will one day return to it. Abhorrence is meant to hurry that process along.
While originally deemed a failure this blade has the ability to grow in size and power as it feeds on the souls it consumes.
Abhorrence's hunger for souls must be regularly fed. If the sword goes three days or more without consuming a soul, a conflict between it and its wielder occurs at the next sunset.
Proficiency with a Dagger allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Nick. When you make the extra attack of the Light property, you can make it as part of the Attack action instead of as a Bonus Action. You can make this extra attack only once per turn.
Notes: Bonus: Magic, Advantage: Ability Checks, Advantage: Saving Throws, Advantage: Melee Attacks, Advantage: Ranged Attacks, Creature of Non-Lawful Alignment, Damage, Buff, Combat, Bane, Sentient, Finesse, Light, Thrown, Nick