While it's in your inventory, killing an enemy grants +9% Life Drain, -9% Damage Taken, and +9% Experience Gain for 9 turns, while also reducing Sanity by 6 and with 33% chance activating Unholy Blessing for 9 turns.
A necromantic artifact created by mages of ancient Axonia and later rediscovered by Venemist. Picking it up instantly fills your mind with barely audible, lingering whispers in a long-dead language...