Tainted Eden

What you start with

The mechanics that actually govern this character.

• Random start like Eden: random health, random active and passive, possibly a trinket, card or pill and some pickups. Stat ranges are damage 3.5 +/- 1.0, tears +0.75 to -0.515, shot speed 1 +/- 0.25, range 6.5 +/- 1.5, speed 1.0 +/- 0.15, luck 0 +/- 1.
• Every hit that is not self-inflicted rerolls everything: all stats, every passive, the active, the trinket and the held card or pill. Self-damage (Blood Donation Machine, Devil Beggar, Curse Room spikes, IV Bag) does not reroll, and fatal damage does not reroll either.
• Unrerollable: The Polaroid, The Negative, Dad's Note, Damocles, Dogma, Key Piece 1/2, Knife Piece 1/2. Missing No. can be rolled INTO but never out of. Duplicate copies of an item always reroll into different items.
• If you hold two trinkets (Mom's Purse, Belly Button) or two actives (Schoolbag), the second slot is dropped on the ground rather than rerolled.

How to play them

• The gimmick in plain language: your build is a slot machine that pulls every time something touches you. You are not assembling a run, you are assembling a POOL of reroll slots plus a small spine of things rerolls cannot take.
• Learn the spine. Surviving a reroll: heart containers from Converter, Empty Heart, Health Up pills and Eternal Hearts; soul and black hearts; Abyss locusts; The Swarm's flies; Sumptorium and Lil Clot clots; friendly monsters from Friendly Ball, Poke Go, Mystery Egg and Friend Finder; Red Stew's damage; Brittle Bones' fire rate; swallowed trinkets; and Esau Jr.'s flight.
• Quantity beats quality. Take every passive you can, because each one is another lottery ticket on the next hit, and multiple copies always land on different items.
• Do not cap out at 12 hearts. Sit around 6 to 9 and leave hearts on the floor to pick up when needed - a reroll into a high-container build makes overflow soul hearts vanish permanently.
• Drop things you are not using right now. Cards, runes and pills left on the floor cannot be rerolled away, and level-generation trinkets (Bloody Crown, Telescope Lens, Fragmented Card) can be dropped in the starting room and collected before you leave the floor.
• After every reroll, re-test what you can do: walk into rocks to see whether you have Thunder Thighs or Leo, and check whether you gained secret-room detection or flight. Half the deaths on this character are from assuming you still have last room's kit.
• Rolls are seeded. Undo a reroll with Glowing Hourglass, get hit again in the same conditions, and you get the same result back - including getting the Glowing Hourglass itself back.

Items to hunt for

Strong on this character specifically, not just strong.

• Birthright: locks everything you own at that moment against ALL rerolls, including D4 and Missing No., not just damage rerolls. It only appears in Shops and can never be rolled into. If you find it and your build is bad, take a couple of hits to fish for something better before you buy it and freeze the run.
• Converter, Empty Heart and PHD (for Health Up pills): permanent red heart containers are the one thing rerolls cannot strip, which makes them the most valuable resource on the character. PHD also permanently raises base stats through stat-up pills, and Guppy's Paw turns containers you were going to lose anyway into reroll-proof soul hearts.
• Damocles: its passive effect cannot be rerolled, and actives CAN roll into it. It is the biggest item-quantity multiplier available to you.
• Holy Mantle, Blanket or Wooden Cross: absorbing a hit with a shield does not trigger a reroll at all, which is the only genuine defence against your own mechanic.
• Book of Virtues taken from a Library: it is the only passive in the Library pool, so it literally cannot be rerolled away.
• Smelter, Marbles or Gulp! pills: swallowed trinkets become permanent. Absorb anything decent the moment you can.
• Panic Button trinket plus a self-damage active such as Razor Blade or IV Bag: self-damage never rerolls, so you get free active triggers with no build risk.

Traps to refuse

Picks that are neutral or good elsewhere and bad here.

• TMTRAINER: every item you pick up afterwards becomes a glitched item, and glitched items stop rerolling, so the mechanic locks up around random garbage. It is the Tainted Eden Beast unlock, so if you want it out of the Secret Room pool for other runs, do The Beast last.
• Missing No.: it does nothing except reroll harder and it usually costs you the Secret Room passive you were carrying.
• Magic Skin: after it is rerolled it keeps replacing future items with more copies of itself, cutting your passive count.
• Genesis: wipes every non-rerollable benefit you had built up and removes itself, which on this character is close to run-ending.
• Anything that pays off on taking damage (Bloody Lust is the clean example) - the reroll takes it before the stacks matter. Void also deletes the stat-ups from everything it absorbed.

Cheese and techniques

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

• Item pool steering, live on 1.7.9 and changed in Repentance+: walk into every item room WITHOUT taking the items, then enter an Angel Room, Planetarium or Shop. On the next damage reroll, every already-generated pedestal rerolls into that pool. Alabaster Box or Keeper's Box spawning a pool-specific item does the same thing.
• Prefer Secret Room ACTIVES over Secret Room passives: actives can roll into R Key or Death Certificate, whereas passives can roll into Missing No. or TMTRAINER.
• Death Certificate is a hard win here because it can hand you Dogma, which is unrerollable.
• Glowing Hourglass has 3 uses per floor on Repentance with unlimited recharge - use it in the same room as a bad reroll to get the old build back.
• The Marked Skull on Depths, Necropolis or Dank Depths II always drops a 0 - The Fool card. Grab it, then drop it on the floor at the start of the Mom fight so a hit cannot reroll it, and pick it back up for the trip to the Strange Door (which consumes The Polaroid or The Negative to open).

Getting the marks

• 7 secrets. Isaac, ???, Satan and The Lamb collectively unlock Nuh Uh!. Mega Satan gives Wild Card, Boss Rush OR Hush gives Soul of Eden, Greedier gives the XXI - The World? card, Delirium gives Corrupted Data, Mother gives Modeling Clay, The Beast gives TMTRAINER.
• Sequence The Beast last on this character specifically: its reward is TMTRAINER, which then pollutes the Secret Room pool for every future run and is uniquely awful for Tainted Eden.
• Mom's Heart and normal Greed carry no secret for tainted characters but both marks still have to be filled for the completed note and for Death Certificate.
• Run everything on Hard - a hard mark fills the normal mark too, and tainted characters get no separate all-hard-marks reward.