Tainted Eden

Tainted Eden is a character added in The Binding of Isaac: Repentance. They are the alternate version of. Unlike other Tainted characters, Tainted Eden has no obvious changes to their physical appearance. Tainted Eden is unlocked by reaching and using either the  or the  to access a special room in one of the walls while playing as Eden.

Like Eden, Tainted Eden starts with random stats, health, possibly some pickups, an active item and a passive item.

Every time they take damage, all of their stats, items (passive and active), their trinket and their currently-held card or pill get re-rolled.

Items are more likely to reroll into other items from the item pool they were obtained from. This goes especially for Planetarium items.

Strategy

 * Keeping some soul hearts or black hearts is beneficial because those cannot be rolled away.
 * If you do happen to see in a shop, consider whether the item set that you have so far is something you want to lock in for the rest of the run.  If it's not, and if you have durable health to spare (from soul hearts or from permanent sources like eternal hearts or Health Up pills), you might want to consider taking damage a couple times to see if your items reroll into something better.
 * This can be especially effective if you have items from the Angel Room Item Pool or the Planetarium Item Pool, if you can lock a powerful item like or that can make for a much more effective run.  If this floor has any curse room items or devil room items this may be the one time it's consistently beneficial to take those, since Birthright will prevent those from rerolling into  if you collect it just after.
 * Gaining heart containers from sources other than passive items, such as Health Up pills or Eternal Hearts is beneficial, because those changes are not rolled away.
 * More than other characters, Tainted Eden benefits from quantity over quality of individual items since the items are likely to get rerolled several times anyway.  Buying as many passive items as you can find, and picking up every passive item from safe item pools, gives more items to reroll and more chances of useful synergies.
 * can be useful for doubling any passive item, because both will be rerolled into separate items.
 * Getting items from more consistently positive item pools can make a big difference. In particular, Angel Room items and Planetarium items usually reroll into their own item pools, almost all of which are beneficial and some are particularly powerful.
 * Avoiding Devil Room and Curse Room passives might be a good idea to reduce the chance of rerolling into a detrimental item like .  It will remove all red health and grant nothing in exchange - the extra lives are likely to be lost from the first hit taken.
 * If you have or  unlocked you may also want to avoid taking Secret Room items, as rerolling into them can add even more unwanted unpredictability to your run.
 * An alternative strategy to avoiding Devil Rooms is to take as many Devil items as possible, to get rid of as many red hearts as you can - You won't have to worry about your red hearts being rerolled away if you're not relying on them to begin with. It requires more skill to depend mainly on soul hearts, however.
 * It can be beneficial to carry a trinket even if it's not one you would normally bother with, because if you are carrying a trinket the trinket will also be rerolled when you take damage.
 * If you find a pill or a card that you want to save for more effective later use, like I'm Drowsy..., Full Health, The Sun, or Chaos Card, you might want to drop it at the beginning of each floor and then go back to pick up before proceeding to the next floor to prevent rerolling it.
 * It can be beneficial to carry bad pills and other consumables you don't intend to use because they may be rerolled into something good.
 * Curse room and Red Chest Actives will frequently roll into, allowing empty hearts from rerolls to be turned into soul hearts.
 * Angel room actives can reroll into, granting two items from a particular pool, while Secret room actives can be rerolled into or.
 * Angel items can be rerolled into for a boss room and  before going down a floor, allowing Eden to reliably gain more angel items.
 * Libraries can be powerful for Tainted Eden. If is acquired from a library, it cannot be rerolled by damage as Book of Virtues is the only passive item in the library pool.
 * Holding NO! when taking a hit will turn your active item into a passive item. This may or may not be desirable, so when trying to reroll an active into something specific, it's advisable to drop the current trinket.
 * Plenty of trinkets don't need to be held constantly to benefit from their effects, so dropping them when they aren't needed is often advisable. In particular, trinkets that affect level generation like Bloody Crown, Telescope Lens and Fragmented Card can be dropped in the starting room of each floor, and only returned to once ready to proceed to the next.

Items
While "good items" and "bad items" are less of a factor of choice than for other characters since they are frequently rerolled, there are some that should be of special notice if found or rerolled into.

Good Items

 * Can be used strategically by entering curse rooms with the invincibility granted by teleporting, and to teleport onto and damage or kill enemies.
 * Allows Tainted Eden to get, which will be a permanent damage up and flight.
 * Can be rerolled, but the locusts are permanent.
 * Adds soul hearts which are a relatively stable form of health for Tainted Eden.
 * Prevents items acquired before Birthright was picked up from being rerolled. This includes normal rerolls from items like and, not only the damage-triggered rerolls.
 * Not much use by itself due to the loss of its effect once rerolled. However, if Rock Bottom is obtained and then 'locked in' with Birthright, it would keep the best value of each stat for every stat reroll and item synergy rerolled for the rest of the run.
 * If Birthright is discovered in a shop it might be worth taking damage a few times to try to reroll a powerful synergy before locking it in with Birthright.
 * Grants red hearts which won't be rerolled away, significantly improving Eden's effective health for the rest of the run.
 * If used after getting hurt in the same room, will return Tainted Eden to their previous build upon landing in the previous room. Should Tainted Eden get hurt again while holding their previous active item, they will always reroll it into Glowing Hour Glass. Knowing this, players can practice a room in which they got hurt once until they clear it perfectly, and keep the prior item set as long as they keep using this strategy.
 * Triggering Holy Mantle will not trigger rerolls, helping Tainted Eden keep their current build.
 * Serves as a weaker version of this, for boss battles only.
 * If this item is rolled into while Tainted Eden possesses empty red heart containers, it may be wise to idle in cleared rooms until reaching max health. From there, Placenta is not likely to be useful since damage will reroll it anyway.
 * If retained long enough to be used a few times, Tainted Eden will be able to gain significant permanent health, which is hard to come by for this character.
 * The effect will remain for the current room even if the item itself is rerolled through damage, providing a helpful boon during boss battles.
 * The temporary damage boost is retained even after the item is rerolled, potentially acting as a semi-permanent item effect until the damage boost is lost completely.
 * The orbital flies granted by do not disappear if the item is rerolled.
 * Lil Clot will persist after the trinket is dropped, acting as a semi-permanent familiar until it dies

Bad Items

 * : Removes all red heart containers, even from sources that are otherwise more durable for Tainted Eden, like eternal hearts and Health Up pills, with zero benefits received in return since the extra lives will be rolled away.
 * Any items from the Curse Room, Red Chest, or Devil Deal item pools can reroll into Dead Cat.
 * The bleeding effect from taking damage will still apply even if Shard of Glass is rerolled, resulting in eventual, constant rerolls unless Tainted Eden picks up a red heart.

Situational Items

 * : Potato Peeler will trigger the damage randomization, but the granted is permanent.
 * : Provides black hearts which are a relatively stable form of health for Tainted Eden. However, using it will also replace the floor's boss item with a Devil deal, which should generally be avoided. No boss items means fewer overall items to reroll, ultimately reducing the chances of rerolling into great synergies.


 * : Removes all red health but grants 6 bone hearts. Can be very strong if taken early or if low on heart containers. On the other hand, if Tainted Eden has a lot of permanent red heart containers from Eternal hearts and Health Up pills, it could be detrimental.


 * : Converts one Red Heart Container into three Soul Hearts. Obtained early enough in a run, it allows for Heart Containers that are granted by items that are likely to be rerolled into soul hearts that can not be rerolled. Because it is an active item, it also can not reroll into On the other hand, there are other ways to get permanent Red Heart Containers, and this item could remove them later in the run.

Trivia

 * The achievement for unlocking Tainted Eden is "The Capricious", a possible name for the character.
 * "Capricious" means "given to sudden and unaccountable changes of mood or behavior," fitting Tainted Eden's concept of complete randomness.
 * In-development, Tainted Eden's effect was a full reroll upon acquiring a new item that excluded the item triggering the reroll rather than having the reroll be triggered by damage. This was changed because in testing players would simply stop picking up items once they found something good enough to be worth keeping.