[Variant] Death Blade of Eiymar (Patreon)

Any sword, uncommon (requires attunement)

Half the blade of this sword is consumed by a dark material that flickers with white energy. You gain a +1 bonus to attack and damage rolls made with this magic weapon. Every time you reduce a creature to 0 hit points with this weapon you capture a fragment of its soul within it and it can hold up to 3 Soul Fragments at a time.

Inquire the Dead. As long as there is at least one soul within the sword, you can summon it as an action. The soul is a harmless spirit and it's under the effect of the Speak with the Dead spell. When the spell ends, all the questions are made, or you dismiss the effect the Soul dissipates into the air, free of the sword's grasp. You lose a Soul Fragment.

Cursed Insomnia. While you have at least one soul within the sword its whispers and wails are always in your head. Every time you attempt to take a long rest you must succeed on a DC15 Wisdom Saving Throw. On a failed save you can't gain the benefits of the long rest this day unless you free all the spirits inside the sword.