Binding of Isaac: Rebirth Wiki

Added in Afterbirth

Mega Blast is an unlockable activated item added in The Binding of Isaac: Afterbirth.


  • Upon use, Isaac fires a giant, incredibly powerful blood laser, similar to the one used by Mega Satan Mega Satan, for 15 seconds.
    • The beam deals Isaac's current damage multiplied by 5 per tick.
    • The beam has enough power to push Isaac backward while being fired and will last between rooms, and across multiple floors.
    • The beam has spectral and piercing effects.
    • The beam can be moved while firing in many angles diagonally.
    • While Mega Blast is being fired, Isaac cannot:
    • The laser extinguishes fires, detonates TNT, and destroys poop.


  • Removed in Repentance Picking up a Lil’ Battery with this item will add 3 to its charge, meaning that 4 batteries are required to fully recharge the item.
    • Added in Afterbirth † / Removed in Repentance A Charged Key will only add 3 charges.
    • Added in Repentance Picking up a Mega Battery will fully charge it twice.
  • Using a 48 Hour Energy pill with this item will fully charge it.
  • Mega Blast has an 80% decreased item pool weight, making it less likely to appear than other collectibles.
  • To unlock Mega Blast, Mega Satan must be defeated with all 13 characters.
  • Added in Repentance It is not recommended to use Mega Blast in fight with The Beast, because its beam forces you into obstacles on the level.


All synergies and interactions pertaining to Brimstone Brimstone pertain to Mega Blast, with the following exceptions and additions:

  • Added in Repentance4.5 Volt 4.5 Volt: Item will gain charges for dealing damage, which is especially effective when fighting bosses with large health pool.
  • Added in RepentanceBook of Virtues Book of Virtues: Spawns red wisps on the middle ring that utilize a miniature Brimstone as their weapon, which requires charging and releasing as usual. Lasers can hit up to 8 times for a total of 20 damage. If Mega Blast is being used, the wisps will continuously fire their laser outward rather than in the direction Mega Blast is firing.
  • Added in Afterbirth †Schoolbag Schoolbag: Beam will continue to fire when switching to another active item. Other active items can be used while the beam is firing.


In-game Footage[]


  • Mega Blast's collectible sprite is called 'Mega Satan's Breath' in the game files, which may be its initial name.


PC WCB1 YZ39 (First floor Devil Room)

PC Normal and hard modes only TQWA 6TQD (Curse Room adjacent to spawn, chest teleports to Devil Room)

PC 3KY4 LSVL (Second floor Devil Room)

PC RZL2 6MQ0 (Starting item as Eden, and will also start with Godhead Godhead)

PC Added in Afterbirth † S3VX RPWZ (Starting item as Eden)

PS4 Added in Afterbirth † XGYR 11TV (Starting item as Eden)

PC Hard mode only L6B9 ZZ22 (Starting item as Eden)

PC Hard mode only NZ7T 4RAJ (Starting item as Eden)

PC Greed mode only W3BZ BBB2 (Starting item as Eden)

PC Greed mode only PGH7 BMRT (Starting item as Eden)

Switch Hard mode only PLXX XCLR (Starting item as Eden)



Bug Bug! If the player continues a run that was exited while Mega Blast was active, Isaac will retain the costume and animation of Mega Blast until the item is used again, but no beam will appear.
Bug Bug! Removed in Repentance If the player uses Glowing Hour Glass while in the room that they used Mega Blast, then the Mega Blast attack will still function, but the animation will be removed, and you reobtain full charge for Mega Blast.