The Heretic

The Heretic is a boss added in The Binding of Isaac: Repentance that can appear in the Mausoleum. Contents • 1 Behavior • 1.1 Phase 1 • 1.2 Phase 2 • 2 Gallery • 3 Notes • 4 Trivia

Phase 1

• During the beginning of the fight, 5 Exorcists, which are shielded and invulnerable, summon The Heretic from a large pentagram, after which they turn into Fanatics.
• The Heretic is incorporeal until all Fanatics and the Pacers or Gushers they turn into are dead, similar to The Haunt's first phase.
• While incorporeal, The Heretic can still do contact damage. Phase 2
• Lobs 7 projectiles that, after landing, burst into 6 fires that spread out in a radial pattern. The landing position of each projectile is marked on the ground.
• The Heretic then follows up by launching itself towards Isaac, creating a radial burst of 8 lines of fire where it lands. It spends a short time readjusting its dislocated jaw before continuing to attack.
• The arena of the Heretic always spawns a number of unlit Fire Places. The Heretic can light up 5-6 of them before firing a purple Brimstone laser that connects all of the lit fires. The order the Heretic lights each fire indicates what order the laser travels.
• These can be extinguished with an explosion, preventing Brimstone lasers from reaching the deactivated Fire Place.
• Dashes off-screen and turns invisible before charging in again, predicting Isaac's movements and attempting to bite down on where Isaac is moving, doing a full heart of damage if the attack connects. It chains this attack a total of 4 times, each time from alternating sides of the room.
• The Heretic occasionally does not finish the fourth charge, instead fading away and quickly charging in one final time from the other side of the screen.
• Upon death, the Heretic's fiery eye drops down and sends out lines of fire in the cardinal directions.

• When not fought as a main boss, such as in a Boss Challenge room or a degraded boss, it will not be preceded by Fanatics and have no first phase.
• The Heretic also cannot perform its Brimstone attack outside of its regular boss room as there will be no unlit Fire Places.
• The Heretic can be instantly killed with Vade Retro if it is at 50% health or below.

• The Heretic originates from a Reddit post by NotYourSaggitarius in 2015, as a versus screen mockup. The boss was later incorporated into the Antibirth mod.
• It appears to be a resurrected variation of The Haunt or The Forsaken.
• The only time the Heretic's empty right eye lights up is during its Brimstone attack.
• The Exorcists that appear during the beginning of the fight to summon the Heretic are found nowhere else in the Mausoleum, unlike in Antibirth, where they were a regularly appearing Monster.
• If The Heretic is destroyed with a Chaos Card before the summoning animation finishes, any remaining Exorcists will become vulnerable and be stuck performing the ritual until they are killed. Bosses Chapter 1 Monstro
• Gemini
• Steven
• Dingle
• Gurglings
• Larry Jr.
• The Duke of Flies
• Widow
• Blighted Ovum
• The Haunt
• Pin
• Famine
• The Fallen
• Headless Horseman Dangle
• Turdlings
• Little Horn
• Rag Man Baby Plum Chapter 1.5 The Rainmaker
• Min-Min
• Lil Blub
• Wormwood
• Clog
• Colostomia
• Turdlet Chapter 2 Fistula
• Chub
• C.H.A.D.
• Gurdy
• Mega Fatty
• Mega Maw
• Gurdy Jr.
• Peep
• The Husk
• The Hollow
• Carrion Queen
• Dark One
• Polycephalus
• The Wretched
• Pestilence
• The Fallen
• Headless Horseman The Stain
• The Frail
• The Forsaken Big Horn
• Rag Mega Bumbino Chapter 2.5 Reap Creep
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• Hornfel
• Great Gideon
• The Pile
• The Shell
• Singe
• Clutch Chapter 3 Monstro II
• Gish
• The Cage
• The Gate
• Loki
• The Adversary
• The Bloat
• Mask of Infamy
• War
• The Fallen
• Headless Horseman
• Mom Brownie Sisters Vis Reap Creep
• The Pile Chapter 3.5 The Siren
• The Heretic
• The Visage
• The Horny Boys
• Mom
• Mom's Heart Chapter 4 Blastocyst
• Mama Gurdy
• Scolex
• Mr. Fred
• Lokii
• The Bloat
• Daddy Long Legs
• Triachnid
• Teratoma
• Death
• Conquest
• The Fallen
• Headless Horseman
• Mom's Heart
• It Lives The Matriarch ??? Hush Corpse Chimera
• The Scourge
• Rotgut
• Mother Chapter 5 Satan
• Isaac Chapter 6 ???
• The Lamb
• Mega Satan The Void Delirium Home Dogma
• Ultra Famine
• Ultra Pestilence
• Ultra War
• Ultra Death
• The Beast Greed Mode Ultra Greed Ultra Greedier The Binding of Isaac: Rebirth
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