Book of Revelations

Gives one Soul Heart, increases the chance for a Devil or Angel Room, and changes the boss of the current floor to a Harbinger if possible.

Quote

"Reusable soul protection"

Effects

• Grants a soul heart upon activation.
• Increases chance for a Devil/Angel Room Door to open by 17.5% if held while killing the Boss of the floor.
• If The Book of Revelations is used at least once in a map, there is a higher chance that a Harbinger will replace the normal level boss.

Found in

• Library
• Treasure Room
• Angel Room (Greed Mode)
• Library (Greed Mode)
• Treasure Room (Greed Mode)