Soul of Cain is an unlockable consumable in The Binding of Isaac, added in the Repentance DLC.

Opens all doors in the room, and creates Red Key rooms on all valid walls.

Will destroy the entrance to the Mirrored World in Downpour / Dross II.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this consumable for the previous Repentance version, check this page instead.

Defeat Hush and complete Boss Rush as Tainted Cain.

The following special synergies and interactions for Soul of Cain have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Soul of Cain

• Unlocks all doors and creates red rooms where possible
• Clear Rune: Recharge 6

The following sounds are related to this consumable.

• Check out the consumable description on the external Isaac Wiki.