Dark Soul is silver Tarot Card obtainable in Snowy Bridge and in Haunted Valley. When it is equipped the player can trigger the Demon Morph with only 50 souls instead of 66. It costs 400 gold. To acquire it, player has to find every secred place (in Snowy Bridge) or cannot collect a single soul (in Haunted Valley).
In Painkiller Hell & Damnation this card can be obtained in Opera House and costs 400 gold. To acquire it, player has to find every secred area.
The demon on the card looks like Alastor but without wings.