Soul Coins

Soul Coins (Wondrous Item, Uncommon) are roughly clay pigeon-sized (~11cm diameter) coins of a rough, dark iron. Soul Coins are formed from the souls of deceased beings who lack the force of will to reforge themselves as a proper Soul Vessel. The exact process by which souls are converted into Soul Coins is unknown

Appearance
On one face of a Soul Coin is an image of the soul trapped within etched into the iron. On the reverse is the mark of Asmodeus, likely to reference where the coin was created.

Mechanics
Soul Coins act as fuel for Infernal War Machines, providing the soul power to engage the engine. Additionally, they may be used as up to 100gp of any material component for spells. When used for spellcasting, a Soul Coin is always consumed on use - even if materials are not normally consumed, and even if the full gold piece limit is not reached or used at all. Each soul coin may be used for a single spell.

History
Lock found a box of Soul Coins in an Infernal War Machine garage and tossed them all into the largest machine's furnace in order to pilot the vehicle through Avernus' Trading Outpost and run over both Aberrations and Fiends.

Another box of Soul Coins was discovered after the Siege on the Trading Outpost and was passed to Tim so that he could research them.

A Soul Coin containing the soul of a Halfing named Merry Rivar was used to summon Alec's familiar, Ulur'aht.