Chaos Zero Nightmare (CZN)ReiBuild and Guide

Character
Introduction

Best guide and build for Rei from Chaos Zero Nightmare (CZN). Rei is a 4 character from the Controller class and Void attribute, who belongs to the Terrascion [SS Edenity] faction.

To learn more about Rei check the sections below. Use the tabs to quickly switch to the kind of information you're looking for.

Update tracker

Last review update

Season 2

Last build update

Season 2

Last profile update*

15.03.2026

*Profile update means updates done to reviews/builds/gear within a season - showing the last date we changed anything on this page.

To learn more about Rei check the sections below. Use the tabs to quickly switch to the kind of information you're looking for.

Profile

Review

Epiphanies

Gear

Deck & Teams

Profile

Cards
Starting Cards:
Card Image
1

Dark Blade

Attack
Attack

100% Damage.​
Card Image
1

Material Regeneration

Skill
Skill

Heal 100%.​

Show Effects

Card Image
1

Strike of Darkness

Attack
Attack

[Lead]

100% Damage.
Increase Damage Amount of Basic Attack Cards by 100% for 1 turn.

Show Effects

Epiphany Cards:
Card Image
1

Resonating Darkness

Upgrade
Upgrade

[Unique]

+40% Damage Amount of cards with Cost 1.

Show Effects

Card Image
0

Snack Time

Skill
Skill

[Exhaust]

Choose 1 card(s) in hand to Exhaust.
Heal 200%.
Draw 1.

Show Effects

Card Image
1

Dark Condensation

Skill
Skill

Choose 1 Attack Card(s) in hand, +100% Damage Amount for 1 turn.
Card Image
1

Predator's Blade

Attack
Attack

250% Damage.
For 1 turn 2 Morale.

Show Effects

Ego Skill:
Card Image
4

Final Shadow

Ego Skill

300% Damage.
Gain 1 AP.
Epiphany Variants:

Epiphany cards are special evolutions for the cards you can obtain while playing the roguelike mode. Only some cards in the character's deck can get Epiphany effects. Since there's quite a lot of them, we don't display them by default - press the button below to show them. There are also Divine variants of Epiphany cards, but we're still working on gathering them.

Card Image
1

Strike of Darkness I

Attack
Attack

[Lead]

150% Damage.
Increases Damage Amount of Basic Attack Cards by 150% for 1 turn.

Show Effects

Card Image
1

Strike of Darkness II

Attack
Attack

350% Damage.
Decrease Damage Amount by 20% for 1 turn.​
Card Image
1

Strike of Darkness III

Attack
Attack

[Lead]

150% Damage.
Discard all Basic Cards, add 1 Hit for each.​

Show Effects

Card Image
1

Strike of Darkness IV

Upgrade
Upgrade

[Unique]

Increase Damage Amount of Basic Attack Cards by 80%.​

Show Effects

Card Image
0

Strike of Darkness V

Skill
Skill

[Retain]

Activate all Basic Cards in hand.

Show Effects

Card Image
1

Resonating Darkness I

Upgrade
Upgrade

[Unique]

+60% Damage Amount of cards with Cost 1.​

Show Effects

Card Image
1

Resonating Darkness II

Upgrade
Upgrade

[Unique]

+40% Damage Amount of Void Card.

Show Effects

Card Image
1

Resonating Darkness III

Upgrade
Upgrade

[Unique]

+40% Shield gain, Damage Amount, and Healing of cards with Cost 1.​

Show Effects

Card Image
1

Resonating Darkness IV

Upgrade
Upgrade

[Unique]

+40% Damage Amount of cards with Cost 1 or less.​

Show Effects

Card Image
0

Resonating Darkness V

Skill
Skill

For 1 turn, +80% Damage Amount of cards with Cost 1.
Card Image
0

Snack Time I

Skill
Skill

[Exhaust 2]

Choose 1 card(s) in hand to Exhaust.
Heal 200%.
Draw 1.​

Show Effects

Card Image
0

Snack Time II

Skill
Skill

[Exhaust][Retain]

Heal 200%.
Draw 2.

Show Effects

Card Image
0

Snack Time III

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust up to 2 cards in hand, then Draw for each Exhausted.

Show Effects

Card Image
0

Snack Time IV

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust up to 1 card from the Draw Pile, then Draw for each Exhausted

Show Effects

Card Image
0

Snack Time V

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust 2 cards in hand, then select and Draw 1 Void card

Show Effects

Card Image
1

Dark Condensation I

Skill
Skill

Choose 1 Attack Card(s) in hand, +150% Damage Amount for 1 turn.​
Card Image
1

Dark Condensation II

Skill
Skill

Choose 1 card(s) in hand, +100% Damage Amount, Shield gain, and Healing for 1 turn.​
Card Image
1

Dark Condensation III

Skill
Skill

For 1 turn, +50% Damage Amount of Void Attack Cards.​
Card Image
1

Dark Condensation IV

Skill
Skill

Choose 1 Attack card(s), +100% Damage Amount until used.​
Card Image
1

Dark Condensation V

Upgrade
Upgrade

Choose 1 Attack Card(s) in hand, +50% Damage Amount.​
Potential
1

Epiphany Bonus

Potential 1

When entering Chaos, obtain 1 random Rare Card with an activated Epiphany.
2

Basic Card Upgrade

Potential 2

Increase Damage, Shield, and Healing Amounts of Basic Cards by 2/20%.
3

Common Card Upgrade

Potential 3

Increase Damage, Shield, and Healing Amounts of Common Cards by 2/20%.
3-1

Basic Card Proficiency

Potential 3-1

Add a 20% DMG-Based Recovery effect to Dark Blade Card.
4

Unique Card Upgrade

Potential 4

Increase Damage, Shield, and Healing Amounts of Unique Cards by 2/20%.
5

Health Proficiency

Potential 5

Increase Health by +1.6/8%
5-1

Basic Card Proficiency

Potential 5-1

+5% Damage for Rei's Dark Blade.
If Rei's Attack is greater than 500, an additional +5% to that value.
5-2

Divine Epiphany Adaptation

Potential 5-2

Increases the chance for a Divine Epiphany to appear by 25%.
6

Attack Proficiency

Potential 6

Attack increases by 1.6/8%.
7

Unique Stat Upgrade

Potential 7

If Rei's Attack is greater than 550, +10% Predator's Blade Damage.
For every 10 Attack exceeding that value, an additional +1% (up to an additional +20%).
Manifest Ego (dupes)
E1

Sleeping Memory

Manifest Ego 1

The Predator's Blade card increases Morale by 2 for 1 turn.
E2

Awakening Memory

Manifest Ego 2

When Rei uses an Attack Card, heal for 120%. This effect triggers only once per turn.
E3

Vivid Memory

Manifest Ego 3

Increase the level of [Basic Card Upgrade], [Unique Card Upgrade], and [Common Card Upgrade] in Potentials by 3.
E4

Inner Memory

Manifest Ego 4

+100% Damage for Final Shadow
E5

Complete Memory

Manifest Ego 5

Increase the level of [Basic Card Upgrade], [Unique Card Upgrade], and [Common Card Upgrade] in Potentials by 3.
E6

Liberated Memory

Manifest Ego 6

Allies' attack card damage is increased by 20%.
Stats (level 60)
HP
313
DEF
186
ATK
392
Gallery

Review

Introduction
Performance Profile

Healing [2/5]

  

Buffs [5/5]

     

Draw [2/5]

  

AP Generation [1/5]

 

Rei is a Void attribute Controller who specializes in buffing her allies whilst offering adequate healing through Chaos. Still, ultimately, it isn't Rei's main goal and isn't something she can excel at compared to other Controllers. 

Rei is proficient at providing huge buffs to her allies' damage output via either Morale or direct card buffs from her Resonating Darkness and Dark Condensation cards, whilst also putting out some damage of her own, thanks to her Strike of Darkness and Predator's Blade’s cards, which also provide temporary one-turn buffs. Rei also offers some light healing, Card Draw and offers a source of [Exhaust] from her Snack Time card.

Rei has some extremely flexible Epiphanies on her cards that can adjust the requirements for her buffs to take place that can allow her to shine even further. Due to the nature of her additive bonuses, she is best paired with DPS characters who have lower base values or multihitters. 

Rei, however, does lack a solid source of healing as her Basic Cards are often removed, but with some Potentials and her Ego2 unlocked, can provide some okay healing when using her Attack Cards. 

If you have a DPS who benefits greatly from small additive damage multipliers or characters who multi-hit, Rei could definitely be one of the best choices to really amp their damage.

Pros & Cons
Pros

  • Incredibly potent and numerous buffing cards and upgrades.

  • Can deal some decent damage herself for a support with Epiphanies that support this.

  • Has [Exhaust]-based Card Draw and deck thinning, which can be enhanced further via Epiphanies.

  • Deals significant Tenacity Damage via Ego Skill.

Cons

  • Most buffs are incredibly specific and conditional.

  • Many buffs last only one turn or work for one specific card.

Ratings

The ratings below are based on the Season Save Data modes and the Chaos Manifestation mode. Each of the modes values different mechanics, so some characters may shine in one of the, while being underwhelming in the other.

T0.5

Chaos Mode

T0.5

Season Save Data

?

Great Rift

Key Mechanics
  • Multiplicative +% DMG: Rei’s kit features both Additive +% and Multiplicative +% DMG buffs and understanding the difference between them is important. Multiplicative +% Increased DMG improves only the base card damage multiplier by the listed amount (e.g., 100% increased by 120% is 240%).

  • Additive +% DMG: Additive +% doesn’t interact with the base damage multiplier of cards and instead adds its listed amount on top of whatever the cards' listed damage shows (e.g, 100% +40% is 140%). 

Potential

Rei’s Signature Potentials mostly enhance her personal damage and not much utility, meaning if you don’t care for that, they are optional.

  • 3-1:  Grants her Dark Blade Attack Card a 20% Damage based Recovery, providing some solid healing that is mostly useful for Chaos. 

  • 5-1: Increases Dark Blade’s damage multiplier by +5% with an additional +5% granted if ATK exceeds 500.

  • 7:  Significantly increases Predator's Blade’s damage by +10% while Rei’s ATK is higher than 550. Also grants an additional +1% multiplier per 10 ATK over 550 up to 20%.

Dupes Review
E0

Base

Base performance of the character.

E1

Ego 1

Rei’s E1 increases the amount of Morale her “Predator's Blade’s” provides by 2 additional stacks for a total of 4 Morale for a single turn. A great first node for Rei that further increases her buffing.

E2

Ego 2

Her second Ego point grants Rei a once-per-turn heal of 120% whenever she uses an Attack Card. A moderately useful node that allows Rei to provide moderate healing whilst also dishing out some damage.

E3

Ego 3

This node increases the base and maximum level of their [Basic Card Upgrade], [Unique Card Upgrade] and [Common Card Upgrade] Potentials by 3. Provides a solid damage and healing boost to Rei’s cards.

E4

Ego 4

E4 enhances the damage dealt by her “Final Shadow” card by an additional +100%. This nearly doubles the damage dealt, which provides a considerable boost to her damaging capabilities.

E5

Ego 5

This node again increases the base and maximum level of their [Basic Card Upgrade], [Unique Card Upgrade] and [Common Card Upgrade] Potentials by 3. Again, primarily enhancing her damage and healing.

E6

Ego 6

Rei’s E6 is arguably one of the largest allures of Rei as a buffer. When unlocked, provides a permanently persisting 20% multiplicative damage buff to all of her allies' Attack Cards. This is an absolutely amazing Potential Node that makes Rei truly shine as one of the best buffers available.

Cards & Ego Skill
Card Image
4

Final Shadow

Ego Skill

300% Damage.
Gain 1 AP.
Final Shadow

Costs 4 EP to use and delivers a solid amount of damage while also recovering 1 AP. The AP is an excellent burst of momentum and the damage can knock out problematic enemies as well. It should be used when you need extra resources.

Card Image
1

Dark Blade

Attack
Attack

100% Damage.​
Dark Blade

Rei’s Basic Attack gains some nice damage bonuses from her Potentials and if needed, serves as a “Basic Attack” for the purpose of her own buffs. Ideally, you would aim to align them with your DPS, though. It also provides ample healing as it will heal for 20% of the damage dealt when her 3-1 Potential has been unlocked.

Card Image
1

Material Regeneration

Skill
Skill

Heal 100%.​

Show Effects

Material Regeneration

Rei’s basic heal. Gains no additional functionality and isn’t an important card for her overall strategy unless you specifically need to boost team healing slightly.

Card Image
1

Strike of Darkness

Attack
Attack

[Lead]

100% Damage.
Increase Damage Amount of Basic Attack Cards by 100% for 1 turn.

Show Effects

Strike of Darkness

Deals some up-front damage, then buffs all Basic Attack DMG by a Multiplicative +100% for 1 turn. This is a potent buff for Basic Heavy DPS, but it isn’t as useful for Combatants that aren’t. This card also has [Lead], allowing it to sometimes be used for free. Should be used before any other cards to capitalize on [Lead].

Card Image
1

Resonating Darkness

Upgrade
Upgrade

[Unique]

+40% Damage Amount of cards with Cost 1.

Show Effects

Resonating Darkness

Another buff, this time an upgrade that persists the whole fight after use. Grants all 1 cost cards an additive +40% DMG, which is generic enough that most DPS can mostly take full advantage. It should be established as soon as possible for maximum value.

Card Image
0

Snack Time

Skill
Skill

[Exhaust]

Choose 1 card(s) in hand to Exhaust.
Heal 200%.
Draw 1.

Show Effects

Snack Time

A heal, draw and targeted [Exhaust] from hand all in one for the low cost of 0AP. To use, a card from the hand must be selected to exhaust for the rest of the combat. This might sound like a downside, but it can simply be treated as a pseudo Card Removal, making it pure upside unless every card in your deck/hand is good. While strong, it also has [Exhaust] itself, meaning it can only be used once.

Card Image
1

Dark Condensation

Skill
Skill

Choose 1 Attack Card(s) in hand, +100% Damage Amount for 1 turn.
Dark Condensation

On use allows 1 Attack Card to be selected and its damage is increased by an additive +100% until next used. A strong and flexible effect, but quite expensive compared to other similar buff effects, which either last multiple turns or affect multiple cards.

Card Image
1

Predator's Blade

Attack
Attack

250% Damage.
For 1 turn 2 Morale.

Show Effects

Predator's Blade

Deals some damage, then grants 2 Morale (additive +40% DMG) for 1 turn. Rei’s most generic and unrestrictive buff, making it one of her better ones baseline, even if the damage boost it offers isn’t the highest for its 1 turn duration.

Best Epiphanies

Best Epiphanies
Note

We have given a star rating for each Epiphany, showing how strong and useful it is - with 1★ being the lowest rating and 5★ the highest.

Card 1
Neutral Epiphany
★★★
Err
★★★
Err
Err
★★
Err
★★★★★
Err
★★★★

Epiphanies:

  • Neutral [★★★] - Target Neutral Epiphany: Draw 1.
    If you are using Strike for its buff, Neutral Draw is one of the most effective ways to–provided you can afford its 1-AP cost. It is recommended to consider this when buffing Basic Attacks and you can afford an extra AP cost every turn; however, it can be hard to get the buff before your other buffs and get past the draw and the AP cost of it versus the consistent buff Strike IV gives.
  • Err
    [★★★] - This is the highest buff amount Strike can give, so it’s certainly worth considering if building around buffing Basics; however, it can be hard to get the buff before your other buffs and get past the draw and AP cost of it versus the consistent buff Strike IV gives.
  • Err
    [] - This is a rather large damage increase to Strike’s base-ratio, but this damage increase is antisynergistic with Rei’s own buffs and comes at the cost of debuffing your ally's damage, so it is not recommended.
  • Err
    [★★] - This is a rather high-Potential card for DPS Rei, but there are a lot of caveats to making it reach that potential, alongside Rei lacking a good partner for increasing her personal damage.
  • Err
    [★★★★★] - Since this is a ‘Starting Card’ and thus hard to remove, making it an Upgrade is one of the best ways to. This also makes the buff permanent, so you no longer lose buffs depending on rotation, making it an amazing choice even if you care about the buff.
  • Err
    [★★★★] - Much like Strike of Shadow IV, giving a card [Retain] is another way to effectively take it out of your deck for no faint cost.

Divine Epiphanies:

Which Divine Epiphany to go for will depend on what your team needs and which Epiphany you chose, but here are the main ones to look out for if you have spare Save Data: Morale/Resolve (Strike of Shadow IV), -1 Cost Reduction.

Card 2
Neutral Epiphany
★★★★★
Card Image
1

Resonating Darkness I

Upgrade
Upgrade

[Unique]

+60% Damage Amount of cards with Cost 1.​

Show Effects

★★★★
Card Image
1

Resonating Darkness II

Upgrade
Upgrade

[Unique]

+40% Damage Amount of Void Card.

Show Effects

★★★
Card Image
1

Resonating Darkness III

Upgrade
Upgrade

[Unique]

+40% Shield gain, Damage Amount, and Healing of cards with Cost 1.​

Show Effects

★★★
Card Image
1

Resonating Darkness IV

Upgrade
Upgrade

[Unique]

+40% Damage Amount of cards with Cost 1 or less.​

Show Effects

★★★★★
Card Image
0

Resonating Darkness V

Skill
Skill

For 1 turn, +80% Damage Amount of cards with Cost 1.
★★

Epiphanies:

  • Neutral [★★★★★] - Target Neutral Epiphany: Morale 1.
    A Neutral Morale Epiphany is more or less the same strength as the best buffs her other options can give, but it makes ⅓ of your buff universal rather than being tied to 1-costs. Being an Upgrade makes it inherently great for thinning her deck via a free removal after Turn 1, as well.
  • Resonating Darkness I
    [★★★★] - The highest buff amount of base Epiphanies. Slightly worse than Neutral Epiphany or more generalizable options in most scenarios, but if buffing 1-costs, it will be your go-to. Being an Upgrade makes it inherently great for thinning her deck via a free removal after Turn 1, as well.
  • Resonating Darkness II
    [★★★] - This Upgrade is great with Void multihitters who have >1-cost costs or as an alternative to Resonating Darkness IV on Void characters who don’t, but can still use both options, such as Chizuru or some Kayron builds. Being an Upgrade makes it inherently great for thinning her deck via a free removal after Turn 1, as well.
  • Resonating Darkness III
    [★★★] - This Upgrade is great for buffing a unit with multi-use 1-cost cards, like Rei herself or like Kayron’s active Futility, as it buffs not only 1-cost damage but also their healing and shielding. Being an Upgrade makes it inherently great for thinning her deck via a free removal after Turn 1, as well.
  • Resonating Darkness IV
    [★★★★★] - Allows her card to not target 0-cost cards, making it more generalizable and synergistic with Cost Reductions on characters like Narja and Chizuru and work with a wider cast of characters. Being an Upgrade makes it inherently great for thinning her deck via a free removal after Turn 1, as well.
  • Resonating Darkness V
    [★★] - Situationally, this option can be strong–especially for OTK. However, losing its Upgrade status makes the buff less constant and makes drawing harder for your deck after Turn 1, so it is not recommended.

Divine Epiphanies:

Which Divine Epiphany to go for will depend on what your team needs and which Epiphany you chose, but here are the main ones to look out for if you have spare Save Data: Morale/Resolve, Draw 1 (Resonating Darkness V).

Card 3
Neutral Epiphany
★★★★★
Card Image
0

Snack Time I

Skill
Skill

[Exhaust 2]

Choose 1 card(s) in hand to Exhaust.
Heal 200%.
Draw 1.​

Show Effects

★★
Card Image
0

Snack Time II

Skill
Skill

[Exhaust][Retain]

Heal 200%.
Draw 2.

Show Effects

★★★★★
Card Image
0

Snack Time III

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust up to 2 cards in hand, then Draw for each Exhausted.

Show Effects

★★★★
Card Image
0

Snack Time IV

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust up to 1 card from the Draw Pile, then Draw for each Exhausted

Show Effects

★★
Card Image
0

Snack Time V

Skill
Skill

[Exhaust]

Heal 150%.
Select and Exhaust 2 cards in hand, then select and Draw 1 Void card

Show Effects

★★★

Epiphanies:

  • Neutral [★★★★★] - Target Neutral Epiphany: +1 AP, Morale 1.
    Because Snack-Time can get Neutral +1 AP, you can get +1 AP and Divine AP for a similar level of AP-Battery to the best AP Batteries–on a draw card. The major downside is that the card will [Exhaust] itself after use. Moreover, it has access to permanent Morale, meaning you can get +4 permanent Morale from 4 Snack-Time dupes.
  • Snack Time I
    [★★] - This option allows you to use Snack-Time one more turn. While useful, it is probably not the preferred option as its use will still be relegated to low turn-counts.
  • Snack Time II
    [★★★★★] - Now, Snack-Time will no longer require an [Exhaust] target, making it much easier to use for more characters who do not always have exhaust targets available.
  • Snack Time III
    [★★★★] - Snack-Time can now Draw 2, as well as target [Exhaust] 2 cards for free (usually targeting Rei’s own cards to get rid of her dead cards for no AP cost). Compared to Snack-Time II, this will be less generalizable but will be much stronger in situations where it is and is still an easy choice if II is unavailable.
  • Snack Time IV
    [★★] - This option allows you to now target a card in the Draw Pile to [Exhaust], which can be nice, but is often not an inherent Upgrade to Snack-Time’s best uses (for low/early-turn content), which makes it not a high recommendation.
  • Snack Time V
    [★★★] - Being able to target-draw a specific Void card is great for supporting a Void character with a set-up where a Void Upgrade needs to be played first, as in certain Kayron builds.

Divine Epiphanies:

Which Divine Epiphany to go for will depend on what your team needs and which Epiphany you chose, but here are the main ones to look out for if you have spare Save Data: +1 AP.

Card 4
Neutral Epiphany
★★★
Card Image
1

Dark Condensation I

Skill
Skill

Choose 1 Attack Card(s) in hand, +150% Damage Amount for 1 turn.​
★★★
Card Image
1

Dark Condensation II

Skill
Skill

Choose 1 card(s) in hand, +100% Damage Amount, Shield gain, and Healing for 1 turn.​
★★
Card Image
1

Dark Condensation III

Skill
Skill

For 1 turn, +50% Damage Amount of Void Attack Cards.​
★★★
Card Image
1

Dark Condensation IV

Skill
Skill

Choose 1 Attack card(s), +100% Damage Amount until used.​
★★★
Card Image
1

Dark Condensation V

Upgrade
Upgrade

Choose 1 Attack Card(s) in hand, +50% Damage Amount.​
★★★★★

Epiphanies:

  • Neutral [★★★] - Target Neutral Epiphany: Draw 1.
    Neutral draw Epiphanies will allow this card to be much more consistent and easy to use if duping around it.
  • Dark Condensation I
    [★★★] - The buff is increased by 50%, allowing it to be used to a higher cap. While great, it doesn’t solve the QoL limitations (lack of draw, AP cost) of the card like other options, making it a great choice if you can work around it, but not preferred if you can’t.
  • Dark Condensation II
    [★★] - The buff is now applied to healing and shielding, which can be useful in some scenarios but is overall more niche than other options.
  • Dark Condensation III
    [★★★] - Now, the buff is exclusive to Void cards, but no longer exclusive to only one card. This is an amazing option for Void multihit DPS, like Chizuru or Renoa. But it makes it a useless buff when not used with Void DPS units.
  • Dark Condensation IV
    [★★★] - Now, condensation will last -until used- which allows for it to be used with turn-skipping setups where one scales at a faster rate than consistent turn-to-turn damage, or if you are just building for a big hit screenshot.
  • Dark Condensation V
    [★★★★★] - This option allows you to permanently buff one card for the rest of the battle. Being an Upgrade makes it inherently great for thinning her deck via a free-removal after Turn 1, as well.

Divine Epiphanies:

Which Divine Epiphany to go for will depend on what your team needs and which Epiphany you chose, but here are the main ones to look out for if you have spare Save Data: Draw 1, -1 Cost Reduction.

Gear

Memory Fragments

The Memory Fragments & Equipment suggestions below are based on calculations we did. If you want to check the damage formula and how scaling the damage works in CZN, check this guide.

Recommended Loadout
1

[4-PC]: When generating or using Exhaust Skill Cards, +5% to Damage Amount of all allies (max 15%).

Flex

Rei is easily able to max out Glory Reign's effect to grant the entire team a 15% (multiplicative) damage boost permanantly so long as she's running multiple Snack Times which most of her most common builds do. It's important to Note that Glory Reign's effect cannot be stacked so you only want to run 1 set of it per team.

Use either 2P Tetra's for a tankiness and a healing boost or 2P Healer's Journey to bolster the overall HP total of the team.

2

[2-PC]: +12% Max HP.

[2-PC]: +12% Defense.

Flex

Only recommended if you already have a 4P Glory's Reign user on your team otherwise you should just use that set instead. If running 2/2/2 though it's best to run 2P Healer's Journey with 2P Tetra's to maximize surviability and healing.

Use either Seth's Scarab to boost the healing and damage output of Basics for early chaos comfort or 2P Blackwing to boost Rei's overall damage output which will also still offers some healing early in chaos runs thanks to the damage to healing conversion from Dark Blade. Alternatively you can also bypass these small bonuses in favor of using non-set pieces to target better main/sub stats.

Main and sub-stats

In a lot of cases, flat sub-stats are better than percentage ones when it comes to HP, ATK and DEF. The reason behind this is that in CZN the characters stats are pretty low and you get more value from flat bonus rather than percentage one based on calcs.

Ideal
HP%
Desire
HP%
Imagination
DEF% = EGO Regen >= HP%
Substats:

DEF > DEF% > EGO Regen = HP > HP%

Partners

Our best Partner recommendation try to balance both the raw damage boost they provide based on our calculations with the additional utility provided by the skill - combined with how it interacts with the characters's kit. We have rated each Partner based on how much additional damage and the utility they provide. Read the comments under each Partner to better understand our reasoning.

No calculations in Chaos Zero Nightmare are completely accurate for all scenarios, including the ones below. What team, decks, epiphanies, gear, equipment, and enemies you’re facing all impact them. Because of this, take the results as guidelines and combine them with the explanations to make your decisions. Calculations use endgame save data set-ups, including 5 turns of combat using the whole deck with all Ego skills unless otherwise stated.

1

Passive - Resonance

The assigned combatant's Defense, Health and healing are increased by 12–20%.

When the assigned combatant Draws for the first time each turn using an ability, +8/16% Damage dealt by allies for 1 turn.

Skill - Errante Hurricane - 4 EP cost

Discard up to 3 cards, then Draw +1 cards equal to the number discarded.

Draw: 5/5
Utility: 1/5
Buffing: 2/5
Survivability: 2/5
Final: 10/20

Nyx is a safe all-around choice for Rei thanks to her ability to churn through 4 cards of the deck with her Ego Skill while also still having some multipliers to survivability and healing. Nyx also does offer a small buff, which is nice, but it's worth noting that after Snack Time is exhausted, Rei doesn't naturally have any other ways to draw in her base card pool, making keeping this buff up dependent on your deck. The one downside of Nyx is that her Ego Skill costs 4EP, which in Save Data game modes usually means you won't be able to easily use it in Turn 1, something the other main supportive Draw Partner Yuri, is capable of. All up, if you need Draw Power or value the Passive stats Nyx provides, she's a safe pick for most teams, but if all you care about is survivability/combo potential, check out other options as they may suit your needs better.

2

Passive - Cantrip

The assigned combatant's Attack is increased by 8/16%.

Upon the first shuffle, the assigned combatant's damage dealt is increased by 8/16%.

Skill - Drone Deployment! - 3 EP cost

Draw 2 Cards.

Draw: 5/5
Utility: 1/5
Buffing: 1/5
Survivability: 1/5
Final: 8/20

Yuri isn't a Controller Partner, so her Passives don't work. However, that doesn't disable her Ego Skill, which is a potent Draw 2 for 2 EP. Yuri is an alternative option to Nyx, which can be used in Turn 1 in Save Data and is far more accessible and spammable in Chaos. If that appeals to you and you're ok downgrading how many cards you're drawing and losing out on all the Passives Nyx provides, you can use Yuri instead.

3

Passive - Starshine Intellect

The assigned combatant's HP and healing are increased by 8/12%.

At the start of the turn, gain [Ponopoko's Cheer] equal to the number of enemies with attack intentions.

[Ponopoko's Cheer]: Incoming Damage is reduced by 10/20%. Upon activation, remove Ponopoko's Cheer (stacks up to 3 times).

Skill - Pokopo ponpon! - 3 EP cost

Heal 200%. Apply 1 Damage Reduction.

Draw: 1/5
Utility: 1/5
Buffing: 1/5
Survivability: 5/5
Final: 8/20

Arwen is one of the top options when it comes to survivability, thanks to her great Passive Stats, which boost both healing and total team health, but most of all her constantly refreshing Damage Reduction. If you're struggling to stay alive and need more survivability, especially in fights that launch large but infrequent attacks, giving up utility or draw for Arwen can be worth considering, especially in Chaos-based game modes.

4

Passive - Alchemical Fruits

The assigned combatant's Defense is increased by 12/24%.

At the end of battle, recover 3/6% Health.

Skill - Vitality Boosting Potion - 2 EP cost

Heal 100%. When in an Injured state, increase Healing Amount by 50%. 1 Morale for 1 turn.

Draw: 1/5
Utility: 1/5
Buffing: 1/5
Survivability: 4/5
Final: 7/20

Alyssa works as an alternative to Arwen with quite a different stat line, favoring Combat Defense and Passive Healing instead. Usually not as universally strong for survivability as Arwen, but if you value the higher defense over Arwen's higher HP total and mitigation buff, she can be a more appealing option.

5

Passive - Bless

The assigned combatant's Defense is increased by 8/16%.

If the combatant ends the turn without using an attack card, Heal 30/60% at the start of the next turn.

Skill - Consecration - 2 EP cost

Heal 100%. For 1 turn, gain 1 Fortitude.

Draw: 1/5
Utility: 1/5
Buffing: 1/5
Survivability: 4/5
Final: 7/20

A F2P survivability option that falls behind both Arwen and Alyssa in most cases, but is still an acceptable choice if you have neither of them available at an acceptable Ego level.

Equipment

In the Zero System, it’s incredibly easy to access all items acquirable via the shop thanks to the five free refreshes you get each shop node - that's why the recommendations below are limited to them only. ATTENTION! Area-specific items can sometimes be more powerful than shop items, but are far less consistent to get or require running a specific world or giving up certain event options. Use the shop list as a starting point for building up your deck saves.

The equipment recommendations are based on items obtainable in Season 2’s Chaos - Burning Life. If you’re running content outside of Season 2, it’s possible some options may not be available for acquisition, or that other options not obtainable in Burning Life may be better.

Weapon
Weapon
DPS
  • -
Support
  • Equipment
    Tentacles of Chaos
     
  • Equipment
    Pale Eternal Flame
     
  • Equipment
    Harp of Conflict
     
  • Equipment
    Harpoon Case of Broken Resolve
     
Armor
Armor
DPS
  • -
Support
  • Equipment
    Star-Lit Cloak
     
  • Equipment
    Vine Camouflage
     
Trinket
Trinket
DPS
  • -
Support
  • Equipment
    Sphere of Randomness
     
  • Equipment
    Shining World Tree Stem
     
Comments - Weapons
  • Equipment
    Tentacles of Chaos
     - Provides 8% Combat Attack to all operators in the team making it the go-to support weapon for most characters not acting as the main DPS when supporting Attack scaling carries providing the Mythic slot isn't required elsewhere.
  • Equipment
    Pale Eternal Flame
     - A potent supportive weapon card for any character ok with giving up their weapon slot for support and who can consistently generate new exhaust cards each turn in order to re-trigger this equipments effect. Grants 10% (multiplicative) damage to the whole team for 1 turn whenever a card is exhausted. Can only be acquired by giving up the copy option though making it hard to include in many support builds.
  • Equipment
    Harp of Conflict
     - A rare but powerful supportive option that grants the entire team 15% (multiplicative) card damage for 1 turn after you've both shielded, healed and dealt damage in the turn. This conditional effect isn't easy to activate for all teams, plus this weapon only comes from Arena Events in S2. When combined this leads to this weapon being strong but both hard to get and only useful in certain teams.
  • Equipment
    Harpoon Case of Broken Resolve
     - An Arena Event exclusive weapon which grants you a card every other turn which costs 0, deals some damage but more importantly applies a stack of Vulnerable, Agony and Weaken enabling many set and equipment effects while also boosting damage. Usually not a competitive pure damage option but a solid supportive pick-up for the debuffs it provides assuming you have the hand space.
Comments - Armor
  • Equipment
    Star-Lit Cloak
     - A generic defensive option usable by all combatants making it a fine supportive addition if no other options are found. However not generally as enticing as direct damage or more immediate utility options for most builds.
  • Equipment
    Vine Camouflage
     - An easy to get and nice inclusion for teams that have use for a powerful (but conditional) survival mechanic. Usually not the most optimal choice within the armor slot for most characters but if you miss no all other options is very easy to pick up as a fall-back.
Comments - Trinkets
  • Equipment
    Sphere of Randomness
     - An exceptionally powerful generic support trinket that grants both 1 draw and 1 AP at the start of battle turbo charging your early game. Is a Mythic item meaning it wont be suitable for every character, but on those who can afford to run it and don't need other accessories in this slot is well worth slotting in if it comes up in your runs.
  • Equipment
    Shining World Tree Stem
     - An option for those looking to increase the total healing output of their team. Not usually favored over more immediately impactful accessory options, but can still be a fine pick-up if nothing else presents itself.

Deck & Teams

Recommended Build
Build Comments
  • OTK Draw - This deck is built around using Rei for Draw in OTK (alongside her other buffs). You want to have as many Snack Times as possible and use them to draw your cards.
  • Basic Attack Buffer - In this deck, you use Strike of Darkness to buff Basic Attacks alongside other buffs through upgrades and Predator Blade.
  • Season 2 Ebony Lumen Draw - A variation of Snack Time draw that instead uses its exhaust effect to activate Season 2’s Ebony Lumen’s incinerate: Draw 3 and net even more draw for OTK.
  • Exhaust Support - Rather than focusing on Draw with Snack Time, this version focuses more on exhausting a lot of cards (and drawing). It’s great for teams that want to exhaust specific cards like Kayron’s Futility.
Removal
  • Dark Blade
     - Removed in basically any Rei deck for Save Data, can be kept in very niche circumstances if doing a Rei DPS build.
  • Material Regeneration
     - Removed in basically any Rei deck.
Conditional Removal
  • Dark Condensation
     - If not buffing one card and you don’t take the upgrade to thin it instead, it will often be removed.
  • Predator's Blade
     - The Morale buff on this is hefty and a keeper for many builds, but for characters who don’t scale well off additive buffs like Nine, she’ll often remove it.
Copying
  • Snack Time
     - Is often the chosen dupe, since Rei is often used for turn-1 draw and exhaust utility. Generically, +4 net draw turn-1 will never be bad.
  • Dark Condensation
     - For builds based around buffing one card to do a lot of damage (like Mei Lin spire), this is the copy of choice, given you have the AP and draw to justify it.
Best Synergies
Best Teams
Chaos Teams
E2 Rei Solo Heal

After her Season-2 Buffs, Rei is an amazing unit for Chaos who can double as both your Healer and Draw (because Snack-Time performs well in low-turn count content, which most Chaos fights tend to be).

E0 Rei Support

Her healing is still not amazing without her E2, unless you get Snack-Time early and end fights very fast. So, it is recommended to have a supplementary healer if your Rei is not E2+.

Save Teams
Generic

As mentioned in other areas, Rei is an extremely flexible unit with whom she can be played with–the main drawback being that she also doesn’t give a lot of value past Turn-1 to a lot of units. Generally, you will prefer to play her with characters who get value out of her buffs, like multi-hitters, or other effects like exhausts in Kayron’s case. However, she can still be played to success with any DPS.