Weapon (Greatsword), legendary (requires attunement by a creature of non-lawful alignment)
You gain a +3 bonus to attack and damage rolls made with this magic weapon. It has the following additional properties.
Spinner's Leech: Whenever a creature is reduced to 0 hit points with The Ebony Blade, the sword grants its user temporary hit points equal to the slain creature's hit point maximum. These hit points fade after 24 hours. As long as these temporary hit points remain, and you keep The Ebony Blade in hand, you have advantage on attacks, saving throws, and ability checks.
Killing a creature in this way devours the soul. Only a Wish spell can return a soul lost in this way.
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, Mephala devours your soul.
Plot Weaver: While you hold the weapon, you are aware of the location of any non-construct or undead creature within 60 feet of you. Charm effects being cast on you cannot succeed.
Oblivion Sworn: (Hidden, even if Identified. A DC 20 Arcana skill check afterwards could uncover the curse.) The Ebony Blade forges a connection between the wielder and the Daedric Prince Mephala. She can communicate with the wielder telepathically.
Once attuned, the wielder does not wish to release control of the weapon. Mephala will attempt to seduce and coerce the wielder to maintain their control of the weapon so that she can feed off the souls of those the weapon slays. She will even attempt to convince the wielder to use the weapon on those who trust the wielder, as the souls of the deceived are far tastier.
Due to Mephala's influence, the wielder is aware of her presence but is unable to speak of her. Mephala demands her blade be used and if a soul is not fed to her for three days, a conflict will occur.
Deceit: (W.I.P.)