Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Mega Satan is a boss that appears in Chapter 6 (Chest Chest, Dark Room Dark Room), and is the final boss of Ending 16.


Mega Satan is located behind the Golden Gate at the starting room of Chest Chest and the Dark Room Dark Room. To unlock Mega Satan, the following criteria must be fulfilled:

  • ??? or The Lamb must have been defeated in an earlier run for the Golden Gate to spawn. Once that is done, the achievement "The Angels Await" will appear.


Passing through the Golden Gate and stepping onto the pentagram initiates the Mega Satan fight.

Phase 1[]

Mega Satan is accompanied by two hands, which serve as a barrier to protect him and an avenue for him to attack. His hands spread apart if Isaac gets close to him, and move together if Isaac moves away from him. Each hand has 600 HP, and destroying a hand deals 100 damage to Mega Satan. Each hand respawns 30 seconds after it’s destroyed.

Mega Satan has the following attacks:

  • Closes his eyes and then fires one of several projectile patterns, including:
    • 3-5 lines of blood projectiles. The angle these shots are fired at alternates between rotating clockwise and counterclockwise. The less lines of projectiles there are, the faster they travel and rotate.
    • Spreads of brown projectiles that split into 4 smaller projectiles after traveling far enough, similarly to 15►Cricket's Body Cricket's Body.
    • 2 spirals of blood projectiles that very rapidly rotate clockwise, creating semi-circular waves of projectiles.
    • Rings of blood projectiles, fired in rapid bursts of 3.
    • 2 spirals of blood projectiles that rotate clockwise at different speeds.
    • 3 lines of blood projectiles that alternate between slowly curving right and left with every shot fired. The angle these lines of projectiles are fired out at alternates between slightly rotating clockwise and counterclockwise.
  • Closes his eyes and then fires a Added in Afterbirth15►Mega Blast Mega Blast laser straight down. His hands always fully spread apart while charging the laser, regardless of Isaac's position.
  • Slams his head into the platforms 1-3 times, creating chaotic bursts of projectiles in all directions.
  • Holds up one hand, then slams it at Isaac, creating a circular rock wave on impact. This attack can’t be used if both hands are currently destroyed.
  • Slams both hands 3 times, alternating back and forth, creating rock waves that move towards the bottom of the screen. This attack can’t be used if either hand is currently destroyed.
    • Destroying a hand during this attack prevents it from creating more rock waves.
  • Mega Satan also spawns sets of mini-bosses to attack Isaac alongside him. These sets can be:
  • After taking enough damage, Mega Satan and his hands withdraw into the darkness behind him and become invulnerable. During this time, he spawns a wave of bosses or mini-bosses, which must be killed in order to make Mega Satan vulnerable again. The first waves of bosses begins after Mega Satan takes 750 damage, the second after 1,500 damage, and the third after 2,250 damage. He will withdraw but not spawn these waves if there are any remaining previously spawned bosses left only when the room is cleared does he spawn the following:

Phase 2[]

After taking 3,000 damage, Mega Satan sinks into the darkness and rises in his final phase as a skull. He no longer has his hands, nor does he spawn bosses; instead, he fires complex projectile patterns. Possible patterns include the ones from the first phase (with increased shot speed), plus:

  • 2 spirals of projectiles that slowly rotate counterclockwise. The shots zig-zag as they travel outward.
  • 2 lines of projectiles that alternate between curving left and right. These lines combine to create curving lines with a safe space that moves from the left of the arena to the right.
  • Rings of projectiles, with every other wave fluctuating in speed as it travels.
  • Many lines of projectiles that slowly curve to the left (if black) and right (if red); these lines create safe spaces to maneuver in that slowly shift to the right.
  • Several lines of projectiles that slowly wiggle as they travel, similarly to Wiggle Worm Wiggle Worm. The angle these shots are fired at either rotates clockwise or alternates between rotating clockwise and counterclockwise.
  • Many lines of projectiles that wiggle as they travel and slowly curve to the left (if black) and right (if red); these lines create unmoving safe spaces between them.
  • Many lines of projectiles that spin as they travel, similarly to Ring Worm Ring Worm. The angle these shots are fired at constantly randomizes.
    • These projectiles don’t travel far enough to reach the corners of the arena if Mega Satan isn’t close to that corner.
  • Dense rings of projectiles that wiggle as they travel.
  • Several lines of projectiles that make large zig-zags as they travel.
  • Six lines of projectiles, half of which slowly curve to the left (if black) and right (if red). These lines create safe spaces that slowly move towards Mega Satan.
  • Rings of projectiles that rotate clockwise (if red) and counterclockwise (if black) simultaneously.
  • Several lines of projectiles that continuously converge onto each other.
    • The projectiles used in these patterns can be colored black, red, brown, or silver, depending on which one is used. For some attacks, they instead appear as red or yellow fire.

As Mega Satan takes damage during this phase, his skull begins to crack before eventually shattering. After this final phase is defeated, the game ends and Ending 16 plays.

  • Added in Afterbirth † If The Void The Void is unlocked, there is a 50% chance that the game does not immediately end, and Mega Satan instead drops an ending chest along with a portal. Entering the chest ends the game and plays the cutscene while entering the portal takes Isaac to The Void The Void.


Unlockable Achievements[]

These achievements are exclusive to Afterbirth, Afterbirth†, and Repentance.

Damage Scaling[]

Damage scaling is an unclear mechanic introduced by Nicalis in The Binding of Isaac: Afterbirth to provide a more challenging experience to the players, enabling some enemies to retaliate against high damage attacks by deploying an "armor" of a sort to greatly reduce the amount of damage taken. Further details and an in-depth explanation may be found here.
Added in Repentance Damage Scaling was given to Mega Satan and his hands in Repentance.


  • Added in Afterbirth Afterbirth added Completion Marks for defeating Mega Satan. In Rebirth, there are no achievements linked to Mega Satan.
  • Mega Satan does not have a health bar, making it difficult to determine how close he is to death.
  • Mega Satan is behind an invisible wall Isaac can't move past, making him immune to contact damage effects like 15►Midas' Touch Midas' Touch and 15►The Virus The Virus.
  • Using Chaos Card on the first phase causes Mega Satan to go into his second phase instead of instantly killing him.
    • This is because the first and second phase of the fight are actually two different enemies, and are shown as such in the bestiary.
  • Mega Satan's hands count toward the mob cap total in the room, and prevent Greed, Sloth, and Fallen Gabriel from spawning enemies while they are undestroyed.
  • With homing tears and 15►The Ludovico Technique The Ludovico Technique the tear will be strongly attracted by the head even when it can't be targeted, making killing other enemies very hard.
  • Unlocking the Golden Gate with the golden key and then restarting the floor with 15►Forget Me Now Forget Me Now or an I AM ERROR room will not cause the golden key to respawn.
  • Added in Repentance Defeating Mega Satan will not revive dead co-op players if the portal to The Void appears.


  • Mega Satan's battle theme is titled Hericide,[1] just like regular Satan.
  • The Mega Satan room is a 1x2 room with only the lower half accessible.
  • Mega Satan's second phase is referred to as "Mega Satan 2" in the bestiary.
  • Mega Satan's second phase has unused sprites of skeletal hands.


Bug Bug! Doing too much damage between phases will cause the game to play the normal "boss defeated" music throughout the rest of the fight.
Bug Bug! If a Pickup spawns under Mega Satan's hand, the hand will start to move and rotate for the rest of the fight until it's pushed away. This is a purely cosmetic bug.
Bug Bug! Added in Afterbirth † Using Delirious in Mega Satan's fight (after stepping on the pentagram), if Mama Gurdy is spawned, Mama Gurdy will be spawned behind Mega Satan, but it will be able to attack.
Bug Bug! If Isaac has Mom's Box and Tick, Mega Satan will start the fight at 70% health, instantly starting the fight at the first wave of bosses. Afterward, Mega Satan will be invisible the entire fight, and if Isaac moves to the upper half of the arena before Mega Satan dies, the game will softlock.
Bug Bug! When playing as Tainted Jacob, Dark Esau is considered a Mini-boss that must be defeated to progress Mega Satan's fight when he spawns Super Sin Mini-bosses.


Bosses Boss Monstro.png
Chapter 1
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GeminiStevenBlighted OvumDingleThe Duke of FliesFamineGurglingsThe HauntLarry Jr.MonstroPinWidowThe FallenThe Headless Horseman
DangleLittle HornRag ManTurdlings
Baby Plum
Chapter 1.5
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Lil BlubWormwoodThe RainmakerMin-MinClogColostomiaTurdlet
Chapter 2
Stage Caves icon.pngStage Catacombs icon.pngStage Flooded Caves icon.png
FistulaChubC.H.A.D.Carrion QueenDark OneGurdyGurdy Jr.The HollowThe HuskMega FattyMega MawPeepPestilencePolycephalusThe WretchedThe FallenThe Headless Horseman
The ForsakenThe FrailThe Stain
Big HornRag Mega
Chapter 2.5
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Reap CreepTuff TwinsHornfelGreat GideonSingeThe ShellThe Pile
Chapter 3
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The AdversaryThe BloatThe CageThe GateMonstro IIGishLokiMask of InfamyWarThe FallenThe Headless HorsemanMom
Sisters Vis
Reap CreepThe Pile
Chapter 3.5
Stage Mausoleum icon.pngStage Gehenna icon.png
The SirenThe HereticThe VisageThe Horny BoysMomMom's Heart
Chapter 4
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BlastocystThe BloatConquestDaddy Long LegsTriachnidDeathLokiiMama GurdyMr. FredScolexTeratomaThe FallenThe Headless HorsemanMom's HeartIt Lives
Sisters VisThe Matriarch
Stage Corpse icon.png
ChimeraThe ScourgeRotgutMother
Chapter 5
Stage Sheol icon.pngStage Cathedral icon.png
Chapter 6
Stage Dark Room icon.pngStage Chest icon.png
???The LambMega Satan
The Void
Stage The Void icon.png
Stage Home icon.png
DogmaThe BeastUltra DeathUltra FamineUltra PestilenceUltra War
Greed Mode
Ultra Greed
Ultra Greed
Ultra Greedier
The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth
Achievements Achievements Attributes Attributes Bosses Bosses TarotCard.png Cards and Runes Challenges Challenges Chapters Chapters
Characters Characters MainPageBabies.png Co-op Items Items Item pools Item pools Monsters Monsters Objects Objects
Pickups Pickups Pills Pills Rooms Rooms Seeds Seeds Transformations Transformations Trinkets Trinkets