Soul Coins are mysterious items that can be found while exploring and completing quests in Baldurs Gate 3. They are generated when a soul is ensnared within a coin, which is then used by devils and their allies as a means of trade and can be exchanged. Soul Coins are created by Mammon and his greater devils on Minauros, the third layer of the Nine Hells, in a vast chamber where the captured souls are tortured and transformed into coins.
In Baldur's Gate 3, Soul Coins have a few uses. They can be used to fuel the Infernal Engine that Karlach has instead of a heart, which gives her a passive buff. Additionally, they can be used to give Karlach a damage buff after you recruit her to your party.
