Devilbox is an active item in neverbirth, a mod for The Binding of Isaac.

While heldEach newly spawned heart pickup has an 80% chance to create an additional full black heart.

When an unvisited Angel Room door appears, there is a 50% chance to convert that floor's deal room to a Devil Room.

On useFirst use per character: gain one full black heart per red heart container.

Later uses attempt to open a Devil Room.

If a Devil Room has not yet been entered on that floor, the first entry after a successful use adds a quality 3 Devil Room item.

After the first use, excess black hearts recharge the box: 1 charge per excess half heart, up to 4 charges.

Related series: Music Boxes.

This item contributes towards the Leviathan transformation. Collecting 3 items from this set will grant Isaac flight and +2 Black Hearts.

Devilbox can be found in the following item pools:

The following tags are applied to this item:

This item uses special charging instead of room-clear charging.

A full black heart can provide 2 charges.

The portion that fits in Isaac's health bar heals first, and only the overflow becomes charge.

Ordinary soul hearts do not recharge Devilbox.

An unsuccessful room-opening attempt preserves the charge.

A previously visited deal room cannot be converted; unsupported rooms or dimensions can prevent opening.

The first use does not open a room or create the quality 3 item.

With no red heart containers, it grants no hearts but still counts as the first use.

Picking up another copy does not reset Isaac's first-use record.

Repeated uses before entering the Devil Room queue at most one bonus item per character.

Bonus hearts created by either box do not create further bonus hearts.

The heart-spawn chance does not stack with additional holders or copies.

The 50% conversion is rolled once per floor when the opposing deal door is eligible; it does not increase the overall chance of a deal door appearing.
Series: Music Boxes.
Music Box / Angelbox.

• Download neverbirth from the Steam Workshop.