Doormaker is a transformation in Benighted Soul, a mod for The Binding of Isaac.

Includes items about keys.
(Detail in GuruWiki)

When a room is cleared, 30% chance to spawn a locked red room, 3 at most for a level.

The 3rd must be Vault.

In Greed Mode, the effect can only be triggered at the starting room when a stage of waves is cleared, and spawns I AM ERROR instead, one at most for a level.

With Hoarding, + 5% chance for each component.

(Vanilla)
Skeleton Key Dad's Key Mom's Key Latch Key Red Key Sharp Key R Key

(Benighted Soul)
Treasure Key AKEY-47 The Silver Key Knock Mom's Old Key Broken R Key Toy Keys Key Walker Spider Keys Mr. Dynamax Brimstone Keys Bob's Blessing Mr. Key Heat Keys Kear Bullet in a Jar Montezuma's Heritage Scatter Keys Bomber Key KKEKK Blood Keys Soul Keys Discount Key The costume is a reference to Slay the Spire 2.

• Download Benighted Soul from the Steam Workshop.