The Ring of Blood Lust is one of 5 rings created by the lesser deity of evil, as a gift to his most faithful followers centuries ago. This particular ring was lost when a devoted priest of the evil god was arrested and executed for using dark sorcery and evil magic many years ago.
The ring was found by a curious human wizard named Jeplet, who has since taken the study of blood magus due to his fascination with the ring. Jeplet now resides in a small cave studying ancient texts of the evil god and trying to please him at every corner to gain acceptance. He emerges from his cave to hunt for sacrifices to the evil god and to eat.
The ring of Blood Lust is a hollow glass ring, and at all tests appears as a Ring of Protection +2. However, once blood is drawn in battle, 8 hollow-tipped spikes emerge on the inside edge of the ring, dealing 1 damage (Concentration check DC 10 to avoid dropping items carried in that hand), and filling the hollow ring with blood. The ring still grants +2 armor class, but also forces the wearer to frenzy (+5 CON, +5 STR and associated bonuses, use barbarian rage rules). Once exhausted, the wearer will stop to consume the blood of his victim, only stopping to defend or bring the bloody corpse to his lair if possible.
The ring also forces the wearer to build a bloody shrine to the god that created the ring, and once per week to perform a bloodletting, dealing 2d6 damage. Also, sacrifices of any live humanoid victim must occur at least once a month, or else the owner will obsessively let blood to try to please the deity to the point of death.
The ring can only be removed by the spell Remove Curse cast by a level 15+ cleric, or on the death of the owner the spikes recede and the ring rolls off the finger.