A Book Crafted of Flesh, Bone and Rotting Skin. Filled with the Souls of Hundreds of Being Humanoid and Non. Though its not only Souls that are Held within the Book.
This Book has 10 Charges, 1d4 Charges are Regained whenever the Creature Attuned to the Book makes a Deal for a Creature's Soul.

You can Expend one of these Charges as a Action to Summon 1 Specter That Lasts for 1d4 + 1 Minutes or Until it is Destroyed.
You can Choose to Expend Four Charges as a Bonus Action to Copy a Creatures Racial Ability, Such as a Dragonborn's Breath Weapon, An Aasimar's Light Wings, or Maybe a Genasi's Innate Magics. Anything Copied in this Way is used as a Bonus Action.
As a Ritual you Can Expend all 10 Charges to Cast either the Animate Dead or the Glyph of Warding Spells.

Notes: Evil-Aligned Spellcaster