Double-tapping a fire button causes Isaac to sneeze blood, dealing damage to enemies in front of him. The sneeze deals damage equal to 1.5x Isaac's damage, knocking enemies and projectiles back. Enemies knocked back take 10 damage when hitting a wall or obstacle and deal 10 damage to other enemies they hit.
The sneeze has a cooldown of 1 second.
The sneeze applies a curse to enemies. Enemies under the curse will take more damage from Brimstone-like laser attacks and violently explode on dying to these attacks, damaging and spreading the curse to nearby enemies. Any enemies spawned by those under the curse will also be cursed.
The following attacks will deal increased damage (2x damage +3):