Tainted Judas

Tainted Judas is a character added in The Binding of Isaac: Repentance. He is the alternate version of, and has an appearance similar to. Tainted Judas is unlocked by reaching and using either the  or the  to access a special room in one of the walls while playing as Judas.

Tainted Judas starts with 2 black hearts and 3 coins. He does not start with like Judas does, but instead starts with  in his consumable slot. When used, Dark Arts gives Tainted Judas +1.0 speed and makes him invulnerable to damage for a short period of time. Any enemies touched while Dark Arts is active will be frozen until the effect ends, at which point they will take damage (x2.5 your damage + 3.5 flat damage). Any enemy projectiles touched while Dark Arts is active will be destroyed. At the end of the effect, a blast effect occurs. The total explosion damage dealt is proportional to the number of enemies touched, and each enemy killed or projectile destroyed grants Tainted Judas a temporary damage boost. The damage boost scales and lasts longer depending on the number of enemies killed and projectiles destroyed.

Tainted Judas is unable to gain Red Hearts. Health Ups will give him Black Hearts instead. Should he pick up a Bone Heart, he will be unable to fill it with red health.

Items & Strategy Notes

 * Tainted Judas is best suited to a highly aggressive playstyle; making effective use of Dark Arts by rushing into the fray and striking as many enemies as possible, then clearing up stragglers with buffed damage. However, it shouldn't be mistaken as a purely offensive tool, as the ability to destroy projectiles gives it great defensive utility when used properly. For example, timing its activation to cross through the origin point of a nova of bullets as they spawn simultaneously removes the need to dodge and grants a massive damage boost.
 * It is vital to get a feel for how long Dark Arts remains active, as being inside an enemy or hazard when it ends will typically result in damage taken.
 * Dark Arts can nullify a lot of the harder puzzle rooms, as one can walk straight through spikes and shots while it's active. In addition, being able to safely enter Curse Rooms grants a risk-free opportunity to build up soul/black hearts or find powerful items every floor.
 * Certain enemies or bosses that rapidly fire bullets, such as Soy Creeps, Revenants, Baby Plum, Hush, etc. are a boon for Tainted Judas; as every bullet walked through contributes to the damage bonus, these can stack up extremely quickly, and as long as the enemy/boss remains alive, this can be repeated indefinitely. This can lead to obscene amounts of damage that can potentially last through an entire run.
 * Tainted Judas is extremely effective in Greed Mode, due to the ability to wholly ignore damage from Curse Rooms / spikes inside the store and the quick transitions between waves allowing for repeated use of Dark Arts to continue stacking damage.
 * Dark Arts can also be used to ignore the damage from the button and pause the timer for free.

Favored Items

 * Due to his similar health system, many of the benefits that apply to in regards to health can be applied to Tainted Judas as well.
 * Items that rely on being in close proximity to enemies can be extremely beneficial, due to how often you will need to sprint through them to build Dark Arts effects.
 * is extraordinarily effective with Dark Arts, as the damage of the Dark Arts hits scales off of the Damage stat, which is increased significantly by Ipecac — it becomes possible to easily shred bosses in a single hit, especially if multiple projectiles are tagged beforehand. However, due to Tainted Judas' low base range, it is easier to hit yourself.
 * As Dark Arts encourages a risky playstyle of throwing oneself into swarms of bullets, items that can block damage while Dark Arts is inactive (such as, , , and ) are very effective.
 * Close-range attack items like, , and will safely damage enemies while using Dark Arts. In a similar vein, charged attacks like  and  will be released when Dark Arts is used, and with careful positioning can provide excellent extra damage.
 * The knife given by the Yes Mother? transformation will still deal damage while using Dark Arts.
 * will not be stopped by Dark Arts, turning it into an instant room clear in many situations and an effective tool for doing damage against bosses.
 * spawns friendly monsters which Tainted Judas can pass through using Dark Arts to obtain the damage bonus without harming them.
 * will effectively halve the time required to charge Dark Arts, making it usable every 3 seconds.
 * doubles the duration of from 1 second to 2 seconds.
 * will group all enemies and projectiles in one place, making it much easier to tag them all with Dark Arts.
 * : Rock Bottom will prevent your damage from decreasing, allowing you to keep the highest achieved damage bonus from Dark Arts.
 * //Beth's Faith: Wisps cannot be destroyed while Dark Arts is in effect and still deal contact damage.
 * will not damage the player while the invincibility effect of Dark Arts is active, making it very useful.
 * can win your run, as you convert one Black Heart into one Black Heart, triggering effect each activation. Spamming it will have no consequences on your health, but will deal constant damages to the enemies.
 * A Missing Page and will add each add +40 damage per activation, killing enemies and bosses up to three times faster.
 * has incredible synergy with Dark Arts, as their damage ups combine together, and Dark Arts can never "miss". This allows Tainted Judas to gain a massive damage boost from one cast of Dark Arts, provided he hits enough valid targets with it.
 * charge is released when using . This allows for safe use of Montezuma's Revenge.
 * The corn shots emitted by Montezuma's Revenge can be destroyed by Dark Arts when standing still, increasing Tainted Judas' damage.

Situational Items

 * The decision to use projectile-destroying items (,, etc.) is one that will need to be judged from playthrough to playthrough. For newer players or during a poor run where damage to oneself needs to be minimized, they are very useful during the downtime between Dark Arts activations. However, for more experienced players or during runs where soul/black hearts are plentiful, they can prove to be quite detrimental as they will block projectiles before Tainted Judas touches them, lowering the Dark Arts damage buff.
 * Orbitals that deal high contact damage (such as or ) work well with Dark Arts, as they deal substantial damage while passing through enemy hitboxes, often enough to negate the damage lost from nullified projectiles. However, enemies killed through means other than Dark Arts will not contribute to its damage bonus.
 * Depending on a player's skill level, items that reduce the size of the character's hitbox (Such as, , and the "One makes you small" pill) may start to become less desirable picks, as they can sometimes make bullets and enemies harder to hit.
 * will increase your damage output with, whether it’s been absorbed or not. When it hasn’t been absorbed, it may cause some confusion as to which character you are controlling, as it looks quite similar to Tainted Judas at a glance.

Disfavored Items

 * Due to his similar health system, many of the detriments that apply to in regards to health can be applied to Tainted Judas as well.
 * takes away all but one of your black and soul hearts on pick up.
 *  should be avoided. The stat-equalizing effect is constantly active, and this weakens Dark Arts in two major ways:
 * It siphons most of the Speed increase during Dark Arts' activation into other stats, most of which are useless as they only benefit tears.
 * Once Dark Arts ends, the damage buff is instead fragmented into various negligible stat bonuses that fall off far too rapidly to be properly utilized.
 * In the same breath, is also recommended to be avoided as it might just give you Libra at the worst possible time.
 * doesn't go invincible when Dark Arts is used, so it is guaranteed to die because of how Tainted Judas is meant to be played, and thus will never pay out — making it useless.

Trivia

 * The achievement for unlocking Tainted Judas, "The Deceiver", may be reference to Judas Iscariot, the disciple who betrayed Jesus Christ, it may also be a reference to the Judas Priest song "Deceiver".
 * The assassin-type design of Tainted Judas, together with the he holds, might be inspired by a (not widely accepted) theory considering that the biblical Judas Iscariot belongs to the Sicarii, a group of Jewish cloak-and-dagger assassins who strongly opposed the Roman occupation of Judea.
 * The Sicarii, named after the word "Sicarius" which means dagger-wielder, are regarded as one of the earliest known organized assassination units of cloak and daggers. Sicarii were known to attack Romans and Roman sympathizers alike with daggers hidden in their cloak, then blending into the crowd after the deed to escape detection. The playstyle of Tainted Judas bears strong resemblance to this, while the sprite of can be a further evidence.
 * Tainted Judas uses a modified version of 's sprites, with the only difference being an additional costume that consists solely of the red cross brand and fez.
 * is Dark Judas' starting item in The Binding of Isaac: Four Souls. As expected, the card and the item have entirely different effects.
 * Tainted Judas starting with 3 coins is possibly a reference to how in The Binding of Isaac: Four Souls, Dark Judas starts with an item called Dark Arts, which gives him 3 coins when anyone rolls a 6.