Tainted Judas

What you start with

The mechanics that actually govern this character.

• The gimmick in plain language: Dark Arts is a short invincible dash. Everything you touch during it - enemies and bullets - gets tagged, and when the dash ends every tagged enemy takes 2.5x your damage plus 3.5 flat, and you get a temporary damage buff sized to how much you tagged.
• The buff is +1 damage per enemy or projectile touched, decaying at -0.25 damage every half second. Dark Arts also gives +1.0 speed while active and destroys any enemy shot you walk through.
• Stats: 2 black hearts, 3 coins, speed 1.23, range 4.5. He can never gain red hearts - Health Ups become black hearts, and a bone heart picked up can never be filled.
• Birthright enlarges the Dark Arts aura so it tags from further away. Car Battery doubles the duration from about 1 second to 2, 9 Volt halves its charge time, and The Battery lets you fire a second Dark Arts while the first is still running.

How to play them

• The correct habit is to time Dark Arts to pass through the ORIGIN of a bullet nova as it spawns, so you eat the whole burst at once. That is simultaneously your dodge and your entire damage curve.
• Get a feel for the duration. Ending Dark Arts while still inside an enemy or standing on spikes is how new players lose runs.
• Bullet-spewing bosses and enemies are gifts, not threats - Soy Creeps, Revenants, Baby Plum, Hush. Every bullet is +1 damage and you can keep re-tagging while the boss lives, so the buff can carry an entire run.
• Free Curse Rooms every floor. Dark Arts is invulnerability, so walking in costs nothing, which is reliable soul and black heart income plus an extra item pool. It also walks straight through spike and shot puzzle rooms.
• Build for damage and speed and stop caring about shot speed, range and tear effects. His kill button scales off the Damage stat, not off tears.
• On 1.7.9, watch what you are standing on when you dash. Running over a card, pill or rune can make you pick it up and then use IT instead of Dark Arts when you press the button, and you eat the hit. Repentance+ changed this; you have the old behaviour.

Items to hunt for

Strong on this character specifically, not just strong.

• Ipecac: Dark Arts hits scale off the Damage stat and Ipecac is a huge flat damage increase, so tagged bosses evaporate in one dash. Mind his low base range when firing normally.
• Rock Bottom: locks in the highest damage the Dark Arts buff ever reached and keeps the Dark Arts speed bonus permanently. Arguably his best item in the game.
• Dead Eye: Dark Arts can never miss, so the multiplier only ever climbs, and its damage ups stack with the tag buff.
• Black Hole: gathers enemies and projectiles into one spot so a single dash tags everything.
• Converter plus Missing Page 2 or the A Missing Page trinket: Converter turns a black heart into a black heart, re-triggering The Necronomicon effect every use, effectively a 3-charge Necronomicon, with each Missing Page adding +40 damage per activation.
• Friend Finder and Montezuma's Revenge: friendly monsters and corn can be dashed through for the damage buff without harming them, letting you pre-charge before a fight. Kamikaze! used inside the invulnerability window gives free repeated explosions.
• Damage blockers for the downtime between dashes: Host Hat, Infamy, Holy Mantle, Belly Jelly. Everything that applies to ??? and black-heart health applies to him.

Traps to refuse

Picks that are neutral or good elsewhere and bad here.

• Libra is the single worst item for him. It bleeds most of the Dark Arts speed spike into stats that only help tears, and it shatters the post-dash damage buff into tiny bonuses that fall off before you can use them. Zodiac is bad by extension since it can hand you Libra at the worst moment.
• Soy Milk and Thunder Thighs: he needs damage and speed specifically and each guts one of them. Dead Cat strips him to one heart of the only health type he can hold.
• Lost Soul is guaranteed to die given how he plays and will never pay out.
• Halo of Flies, Psy Fly and other shot-blockers are a real tradeoff: they destroy projectiles before you can touch them, directly reducing your damage buff. Take them only if the downtime is killing you.
• Finger!, Pointy Rib and low-level Cube of Meat can kill enemies before you reach them once your damage is high, stealing your tags; Broken Modem changes enemy shot patterns and costs you predictable bullet walls.

Cheese and techniques

Verified against 1.7.9 on console — anything patched, PC-only or Repentance+ only is called out rather than listed.

• Greed Mode is his best mode in the game. Wave transitions are fast enough to keep re-dashing and stacking damage between them, every floor has a free Curse Room, and Dark Arts ignores the button's damage while pausing the wave timer.
• Curse Room farming: enter with Dark Arts every floor for free black and soul hearts plus an extra item pool at zero health cost.
• The Ludovico Technique: the tear stays floating while Dark Arts is active, so you can park it on a boss and dash-hit at the same time.
• Judas' Shadow revives him as Tainted Judas rather than as a different character, so it is a genuine extra life for him specifically.
• Known bug to avoid rather than exploit: using Pause while in the Dark Arts state locks him in shadow form unable to fire, and only quitting and reloading the run fixes it.

Getting the marks

• 7 secrets, not 14. No unlock for Mom's Heart, none for normal Greed Mode, and no Hard-mode-sheet co-op baby.
• His 7: any one of Isaac / ??? / Satan / The Lamb gives the Your Soul trinket; either Boss Rush OR Hush gives Soul of Judas; Mega Satan gives Black Sack; Ultra Greedier gives I - The Magician?; Delirium gives Dark Arts as an item for others; Mother gives Number Magnet; The Beast gives Sanguine Bond.
• Ultra Greedier is one of his easiest marks in the game because Greed Mode plays to every strength he has - do it early rather than saving it.
• Boss Rush and Hush are also comfortable, since both are dense bullet fights and that is exactly what stacks his damage buff.