BC7 Backstab is an unlockable challenge in Benighted Soul, a mod for The Binding of Isaac.
This challenge is played on Hard mode.

Steam Sale
Backstabber
Berserk!
Bomb x 9
Posture! (Consumable slot)

Note: this list does not include characters' default starting items.

Permanent Wrath.

Any effect that tries to enter Calm leading to Wrath.

Based on the rules set in the .xml file, the following special rooms are disabled during this challenge:

The following is unlocked for completing the BC7 Backstab challenge: Benighted Samson starts with a random reverse tarot card.

And after clearing Boss Room, common tarot and reversed tarot appear alternately.

Unlock Benighted Samson.

• Download Benighted Soul from the Steam Workshop.