Soul coin

Small, coin-shaped objects made of infernal iron, each containing a bound mortal soul, used as currency in a fictional or fantasy setting. Soul Coins serve as a medium of exchange and a source of power, often utilized in dark rituals or to fuel infernal machinery, setting them apart from conventional currencies. They are primarily relevant to characters and entities within the fantasy world who engage in dark magic, infernal dealings, or require a potent source of energy.