Fiend Fire is an unlockable consumable in Repentance Plus, a mod for The Binding of Isaac.

Sacrifices all of Isaac's pickups and deals damage to all enemies in the room depending on the amount of pickups sacrificed. Can consume up to 80 pickups.
• 3-20 total: deals 15 damage to all enemies and inflicts burn for 4 seconds; burn deals Isaac's damage.
• 21-40 total: initial damage and burn damage are doubled; destroys obstacles around Isaac;
• 41-80 total: burn damage is quadrupled; produces a Mama Mega! explosion in the current room.

Defeat Ultra Greed as Tainted Azazel.

The following special synergies and interactions for Fiend Fire have been documented.

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

The following sounds are related to this consumable.

• Check out the consumable description on the mod's external Wiki.
• Download Repentance Plus from the Steam Workshop.