Chaos Zero Nightmare (CZN)ReiBuild and Guide

• 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%).

4

Final Shadow

Ego Skill

300% Damage.
Gain 1 AP.

Final Shadow

Costs 4EP 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.

1

Dark Blade

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.

1

Material Regeneration

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.

1

Strike of Darkness

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 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.

1

Resonating Darkness

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.

0

Snack Time

Skill

[Exhaust]

Choose 1 card(s) in hand to Exhaust.
Heal 100%.
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.

1

Dark Condensation

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.

1

Predator's Blade

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.

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

• 3-1: Increases Dark Blade’s Crit Chance by +15%.
• 5-1: Increases Dark Blade’s damage multiplier by +5% with an additional +5% granted if ATK exceeds 500.
• 7: Significantly increases Blade of the Predator’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%.

Standard Playstyle

Rei is primarily a buffer focused on increasing your main DPS’s damage through her temporary but powerful amplification, but can also fit within a sub DPS role as well, thanks to the fact that many of her buffs affect her as well. The difficulty in playing Rei is balancing the cost of her buffs against the option of simply using more attacks. Is using two buffs on a single attack better? Or should you use one buff and two attacks? Depending on your team, other buffs, and the hand you’ve drawn, the answer can change frequently.

Note

For every Epiphany, we're colored their name based on how useful we think it is compared to the other variants. Here's the key to the colors:

• Epiphany Name - the best variant,
• Epiphany Name - a good variant,
• Epiphany Name - a niche variant.

Recommended Loadout

2-PC Bonuses

• 

  Tetra's Authority [2-PC]

  - 12% defense passively, which boosts healing a good amount but also contributes to the whole team's tankiness. Best 2P option for Support Rei.
• 

  Healer's Journey [2-PC]

  - A solid boost to overall team survivability via a 12% HP boost, not game-changing, but will help survive large one shots.
• 

  Seth's Scarab [2-PC]

  - Boosts Basic Heal, Shield, and Damage cards by +20% multiplicatively. Strong if you’re leaving in any of Rei’s basic cards, but solid even if you’re not when playing Zero System. Mainly used because there are very few viable set options left.

Weapon

• Flex

Armor

• 

  Reinforced Combat Suit
• 

  Assault Boots
• 

  Survivor's Hood
• 

  Standard Gas Mask

Trinket

• 

  Grey Orb
• 

  Water Drops of the Goddess
• 

  Magic-Infused Sapphire

Comments - Weapons

1. Flex - Some Rei builds deal a bit of damage while others focus completely on support. Support Rei doesn’t have much synergy with any of the shop weapons. Instead, use an Event/World item, fill it with a selection of your choice, or when focusing on offense, lean into a damage boosting choice instead.

Comments - Armor

1. 

   Reinforced Combat Suit
   - Grants a 60% fixed shield at the end of every turn as long as you have no shield before clicking the end turn button. Solid for granting a little extra sustain every turn in shieldless teams. Multiple instances of this equipment also work and stack together, allowing for up to 180% end-of-turn fixed shield. Useless when run with active shielders, though.
2. 

   Assault Boots
   - Deploys a 200% fixed shield on the 2nd turn of combat. A strong one-off shielding option that triggers on a turn when enemies are very likely to be attacking you. An okay option in short fights, but loses value in longer ones.
3. 

   Survivor's Hood
   - Offers a 140% fixed shield on the 1st turn of combat. A smaller shield than Assault boots, which, when combined with the fact that many enemies use their first turn to buff themself or debuff you, makes it slightly less appealing. Still a reasonable choice, though, and better than nothing.
4. 

   Standard Gas Mask
   - A non-shield option that grants 1 stack of immunity, blocking a debuff incoming from enemies. If you’re having no issues with survivability, it can actually be more beneficial than shielding, also stacks with other characters using it, granting up to 3 immunity at the start of battle.

Comments - Trinkets

1. 

   Grey Orb
   - An always useful option which grants you 3 stacks of damage reduction at the start of the fight, reducing the first 3 hits you take by 15%. Strongest against single-hit bosses, not as useful against many small or multi-hit foes.
2. 

   Water Drops of the Goddess
   - Applies 1 stack of the Save buff at the start of battle, which preserves AP for as long as it persists, but 1 stack is removed at the end of each turn. In most cases, it will allow you to transfer any AP you don’t spend on turn 1 of the fight to turn 2. If this sounds useful, having this on your support is a good idea; if it doesn’t, other options are likely better.
3. 

   Magic-Infused Sapphire
   - Inflicts 1 full bar of Tenacity to all enemies at the start of the battle, assuming you have an Initiation card in your hand, regardless of which combatant it belongs to. A good way to accelerate breaking enemies and accessing extra AP, also stacks between multiple combatants, allowing you to inflict up to 3 bars at the start of the battle if all your characters have it. Rei herself doesn’t have any Initiation cards, but she can still trigger this off of other characters.

Important!

CZN is a game of randomness; sometimes you’ll be offered generic or Divine epiphanies that are stronger than a character's standard five options. In these cases, breaking the listed build can result in an even more powerful save. Adjust as you see fit!

Build Comments

As a support capable of buffing a wide range of strategies, Rei has many different viable epiphany options, which we’ll be explaining in detail in the Epiphany Alternatives section below. The build we’ve linked, “Generalist Rei” is the most all-around build you can construct for her without specializing toward any particular play style or character. You’ll likely find optimizations depending on your team, though.

Card Removal Priority

• Dark Blade: While Rei can be built to deal damage, it’s usually not her main role. When playing her as a support, consider removing both basic attacks unless you specifically want to keep one to trigger her E2 heal.
• Material Regeneration:: This card is one of Rei’s only sources of healing outside of Snack Time, which has Exhaust and her E2, which relies on attacks. If you need Rei’s help in healing, consider keeping this card; otherwise, remove it to slim down her deck size.
• Strike of Darkness: This card's most commonly chosen Epiphanies are completely reliant on either activating or buffing basic attacks. If your team uses Basics, it’s one of her top cards and worth keeping; if you’re not, it’s nowhere near as useful and can be removed.

Card Dupe Priority

Dupe Priority

Snack Time II >= Predator’s Blade >= Dark Condensation V

Depending on what you need from your Rei, your Dupe priority will change. The safest dupe choice is Snack Time II as a draw 2 and heal for 0 AP, which also has Retain is never bad. But you may also want to consider duping Dark Condensation V or Predator’s Blade for superior buff potential.

Note: With E1 active, Predator’s Blade grants 4 Morale instead of 2, allowing it to outperform Dark Condensation unless you’re specifically after the permanence of condensation V, which persists between turns.

Epiphany Alternatives

• Snack Time: Snack Time II is generically good and works in every build, but some of the other epiphanies can also be helpful depending on your needs. Exhausting cards in your deck is a very potent effect for achieving smaller deck sizes, something that II, III, IV, and V all achieve. If this appeals to you, consider them. The fact that Snack Time V also searches for any Void card should also be considered.
• Strike of Darkness: There are two incredibly compelling choices for this card for decks using basics. Strike of Darkness V allows all basics in the hand to be played for free at the cost of 0AP, making it a very strong combo piece in basic-heavy decks. If you don’t need the help casting basics, though, Strike of Darkness IV is an upgrade that grants +80% multiplicative damage to all basics, amplifying their damage significantly. Both are incredibly strong and viable; it just depends on which one your build needs more.
• Resonating Darkness: Resonating Darkness I, II, III, and IV are all viable; you’ll need to choose the one that’s most applicable to the deck you’re planning to play.
• I: Best for decks that use mostly 1-cost cards to deal their damage
• II: Strongest for Void Decks that use a mix of different costs all at once and can’t use Reso I effectively.
• III: Boosts 1 cost healing and shielding as well as damage in exchange for lower buffing potential. Strong if you need extra sustain, and it happens to be 1-cost.
• IV: Most general buffing choice which works on all 1-cost and below cards, which covers most character kits.

The entirety of Rei’s kit focuses almost exclusively on providing a heap of temporary and permanent additive DMG% to allies. This is, for the most part, incredibly generic and very potent for any character that either attacks a lot or has abilities that are multi-hit in nature. In addition to this, Rei also has outstanding Basic card synergy thanks to Strike of Darkness, further expanding her usefulness. Due to how generic and flexible her kit is after epiphanies, Rei really works with anyone with a high hit count;

Rin

Renoa

Tressa

Important!

If you’re losing runs when playing a damage-focused composition either to sanity or dying, consider using a team with more defensive characters - so including both a shielder and healer. This is especially important in the Zero System mode.

Generic Rei Team

Damage

High hit count DPS

Support

Flex

Support

Shielder