Black Moon is a passive item in Fiend Folio, a mod for The Binding of Isaac.

When Isaac kills an enemy with his tears, they will create a large red aura with a cross in the center that damages enemies inside it.

The aura's damage scales with Isaac's damage and tears stats, using the formula: 5 × DamageStat / max(MaxFireDelay, 0.01) × 0.5. The damage cannot go below 2.5.

Enemies killed by the aura cannot spawn additional auras.

The aura lasts for 3 seconds before disappearing, and deals damage 6 times per second.

The size of the aura scales with the enemy's maximum HP, and Isaac's range stat, however it has its lower and upper limits.

Black Moon can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for Black Moon have been documented.

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

• Check out the item description on the mod's external Wiki.
• Download Fiend Folio from the Steam Workshop.