The Gaelean Chronicles: Heroes 4 Hire
Unholy Relics of Evil (Cursed)
Wondrous item, Unique
These vessels are ancient relics that have been used in vile rituals for centuries and have absorbed the evil of their users. A character who touches one of these vessels must make a DC 13 Charisma saving throw. On a save, the character senses the relic’s unholy nature and can put the item down. On a failed saving throw, the character falls under a demonic curse and refuses to part with the vessel or to allow others to handle it. After six days, the character becomes a servant of the cult and returns to this chapel. If still in possession of the relic, he or she replaces it on the altar and then stays on as a guard.
Casting Dispel Magic and Bless on the afflicted character has a 60% chance of removing the curse; Remove Curse works automatically. Each day the character remains cursed after the first, the 60% chance drops by 10%. When the chance drops to 0%, even Remove Curse fails. Such spells might be available from higher-level clerics, assuming the characters have made such allies.