Table of Contents
- 1 Cassius Overview in Chaos Zero Nightmare
- 2 How to Get Cassius in Chaos Zero Nightmare
- 3 Best Team Compositions for Cassius
- 4 Best Cassius Build and Cards
- 5 Best Partner
- 6 Best Memory Fragments for Cassius
- 7 Best Equipment for Cassius in CZN
- 8 Cassius Cards in Chaos Zero Nightmare
- 9 Ego Skill
- 10 Potential Upgrades
- 11 Manifest Ego
- 12 How to Play Cassius in Chaos Zero Nightmare
Cassius is a 4-star Controller from Chaos Zero Nightmare. He uses the Instinct attribute and belongs to the Peltion faction. He works as a universal support specialist who manipulates card draw and searches through Quest mechanics, enabling combo-heavy teams to assemble their win conditions consistently.
Cassius Overview in Chaos Zero Nightmare
 | Overview | ||
| Type | Controller | ||
| Attribute | Instinct | ||
| Faction | Peltion [Company 110] | ||
| Rarity | ☆☆☆☆ | ||
| Voice Actor (EN) | Voice Actor (JP) | ||
| - | Kohsuke Toriumi | ||
| Gender | Race | Gift | Birthdate |
| Male | Cyborg | Blink | July 7th |
Cassius Stats
| Stat | Value |
|---|---|
| Attack | 129 (base) / 393 (level 60) |
| Defense | 56 (base) / 186 (level 60) |
| Health | 74 (base) / 383 (level 60) |
| Critical Chance | 3% |
| Critical Damage | 125% |
How to Get Cassius in Chaos Zero Nightmare
Cassius is available through standard rescue banners and event rewards in Chaos Zero Nightmare as a 4-star character.
Best Team Compositions for Cassius
Recommended Team Setup (Triple-0 Combo)
| Position | Character |
|---|---|
| Main DPS |  Tressa |
| Support |  Mika |
| Sub-DPS/Support | Cassius |
Cassius excels in this specialized Triple-0 Quest team where Tressa generates massive amounts of Shadow Daggers (0-cost cards) through her Shadow Reload epiphany. Mika provides 0-cost healing cards that trigger Tressa's Shadow Reload, creating a loop where Cassius completes the Triple-0 Quest multiple times per turn.
Universal Support Team
| Position | Character |
|---|---|
| Main DPS | Any Combo DPS (Renoa, Kayron, Yuki, Hugo, Luke) |
| Healer/Support | Mika / Veronica |
| Support | Cassius |
Cassius functions as a universal support who fits into virtually any team composition.
Alternative Team Members
| Character | Explanation |
|---|---|
 Hugo | Works exceptionally well with Cassius. |
 Luke | Luke's abundant 0-cost and 1-cost Bullet cards easily complete Triple-0 and Triple-1 Quests multiple times per turn, making Cassius a secondary DPS. |
Best Cassius Build and Cards
Core Character Cards
| Card Name | AP Cost | Type | Effect | Tags |
|---|---|---|---|---|
 Pop Eyed Popper | 0 | Upgrade | Effect: From 4 Quests, choose 1 to begin | - |
 Devil Dice | 0 | Attack | Draw 1 80% Damage to all enemies equal to that card's cost | - |
 Shuffle | 1 | Skill | Move all cards from hand and Discard to Draw Pile, then Draw 5 | Exhaust |
 Dice Trick | 2 | Upgrade | On Quest completion, create 1 Quest Card(s) | - |
 Joker | 1 | Skill | Select 1 card from Draw Pile to Draw | Discard Pile, Draw Pile, Draw |
Best Partner
Recommended Partner Choice
| Aspect | Details |
|---|---|
| Partner Name |  Nyx |
| Passive Effect | Assigned combatant's HP and healing +8%. When assigned combatant Draws for first time each turn using ability: +8% Damage to allies for 1 turn. |
| Ego Skill | Discard up to 3 cards, Draw +1 per discarded |
Best Memory Fragments for Cassius
Set Combination
| Set | Stats Priority |
|---|---|
| 2-piece: Healer's Journey Set / Tetra's Authority Set | HP, HP%, Defense |
| 2-piece: Black Wing Set | HP, HP%, Defense |
| 2-piece: Cursed Corpse Set / Seth's Scarab Set | HP, HP%, Defense |
The 2/2/2 setup prioritizes survivability over damage for Cassius. Healer's Journey grants +12% max HP, crucial for reaching the 700 HP threshold required by Potential 7. Black Wing provides +12% Attack for his damage-dealing Quests. The flexible third slot can be Cursed Corpse (+20% damage to Agony targets) when paired with Tressa, Tetra's Authority (+12% Defense) for tankiness, or Seth's Scarab (+20% Basic card damage) for early Chaos runs.
Best Equipment for Cassius in CZN
| Equipment Slot | Recommended Item |
|---|---|
| Weapon | Unexploded Plasma Bomb |
| Armor | Regenerative Ribcage |
| Accessory | Revelation's of Futility |
Cassius Cards in Chaos Zero Nightmare
Basic Starting Cards
| Card Name | AP Cost | Type | Effect | Tags |
|---|---|---|---|---|
 Card | 1 | Attack | 100% Damage | - |
 Wild Card | 2 | Attack | 220% Damage | - |
 Mana Field | 1 | Skill | Heal 100% | Heal |
Unique Cards
| Card Name | AP Cost | Type | Effect | Tags |
|---|---|---|---|---|
Pop Eyed Popper | 0 | Upgrade | Start 1 random Quest out of 4 | Initiation, Draw Pile, Draw |
Joker | 1 | Skill | Select 1 card from Draw Pile to Draw | Discard Pile, Draw Pile, Draw |
Cards with Epiphanies
| Card Name | Epiphany 1 | Epiphany 2 | Epiphany 3 | Epiphany 4 | Epiphany 5 |
|---|---|---|---|---|---|
Pop Eyed Popper | Start random Quest (0 cost, Initiation) | Start random Quest, Quest Card removes Ephemeral and gains Retain (0 cost) | Start random Quest, create stronger Quest Card on completion (0 cost) | Choose 1 of 4 Quests to begin (0 cost) | Start random Quest, replace with another random Quest on completion (0 cost) |
Devil Dice | 200% Damage, Create 1 Quest Card (1 cost) | 160% Damage, Draw 1 (1 cost) | 160% Damage to all, Draw per target hit (1 cost) | 240% Damage, Draw 2, Discard 2 (1 cost) | Draw 1, 80% Damage to all equal to drawn card's cost (0 cost) |
Shuffle | Discard all hand, Draw equal number (1 cost, Exhaust) | Discard any number from hand, Draw same number (1 cost, Exhaust) | Move all cards from hand and Discard to Draw Pile, Draw 5 (1 cost, Exhaust) | Select up to 5 from Discard to place on Draw Pile top (0 cost, Exhaust) | Draw 3, if total cost ≤4: Discard all (0 cost, Exhaust) |
Dice Trick | 360% Damage, Decrease cost by completed Quests (2 cost) | 300% Damage to all, Decrease cost by completed Quests (2 cost) | 80% Damage, +80% per completed Quest (0 cost) | When Quest Card used: Heal 100%, 100 Fixed Damage to random enemy (2 cost, Upgrade) | On Quest completion: create 1 Quest Card (2 cost, Upgrade) |
Generated Cards (Quest Cards)
| Card Name | AP Cost | Type | Effect | Tags |
|---|---|---|---|---|
 Quest: Triple 0 | 0 | Upgrade | When using 3 cards costing 0: create Triple 0 | - |
 Quest: Triple 1 | 0 | Upgrade | When using 3 cards costing 1: create Triple 1 | - |
 Quest: Straight | 0 | Upgrade | When using cards costing 0, 1, and 2 each: create Straight | - |
 Quest: Full House | 0 | Upgrade | When each combatant uses a card: create Full House | - |
Triple 0 | 0 | Attack | 40% Damage per Attack Card used this turn | Exhaust, Ephemeral |
Triple 1 | 0 | Attack | 90% Damage, Heal 90% | Exhaust, Ephemeral |
Straight | 0 | Skill | For 1 turn: 2 Morale, Resolve, Fortitude | Exhaust, Ephemeral |
Full House | 0 | Skill | Draw 1 | Exhaust, Ephemeral |
Ego Skill
| Aspect | Details |
|---|---|
| Skill Name |  Death Trick |
| Effect | Create 2 Quest Cards, -3 Morale to all enemies for 1 turn (E4: -5 Morale) |
| EP Cost | 4 |
Potential Upgrades
| # | Upgrade Name | Effect | Cost |
|---|---|---|---|
| 1 | Epiphany Bonus | Upon entering Chaos, obtain 1 random Rare card through Epiphany | 8x Common Growth Stone of Instinct, 10,000 Units |
| 2 | Upgrade Basic Cards | Basic Card damage, shield gain, healing amount +2% per level (max 20%) | 4x Common Growth Stone of Instinct, 3,000 Units |
| 3 | Upgrade Neutral Cards | Neutral Card damage, shield gain, healing amount +2% per level (max 20%) | 5x Great Growth Stone of Instinct, 16,000 Units |
| 3-1 | Basic Card Proficiency | Card and Wild Card: 30% chance to Draw 1 | 16x Great Growth Stone of Instinct, 24,000 Units |
| 4 | Upgrade Unique Cards | Unique Card damage, shield gain, healing amount +2% per level (max 20%) | 8x Great Growth Stone of Instinct, 20,000 Units |
| 5 | Health Proficiency | +1.6% Health per level (max 8%) | 16x Premium Growth Stone of Instinct, 28,000 Units |
| 5-1 | Basic Card Proficiency | +5% Damage for Card and Wild Card. If Health > 600, additional +5% | 16x Premium Growth Stone of Instinct, 2x Shards of Condemnation, 60,000 Units |
| 6 | Attack Proficiency | +1.6% Attack per level (max 8%) | 120x Premium Growth Stone of Instinct, 42,000 Units |
| 7 | Upgrade Unique Stats | On Quest completion: gain 1 Morale for 1 turn. If Health > 700, gain additional 1 Fortitude for 1 turn | 36x Premium Growth Stone of Instinct, 2x Shards of Condemnation, 80,000 Units |
Cassius has relatively weak potentials compared to other characters, but Potential 7 is game-changing. Gaining 1 Morale per Quest completion means completing 3 Quests in one turn grants 3 Morale stacks (60% damage buff) to your entire team. In Triple-0 builds where you complete 10+ Quests per turn, this becomes absurd. The Fortitude bonus (if HP > 700) provides defensive scaling. The 3-1 potential adds minor card draw to basics but isn't impactful since you'll remove those cards in optimized builds.
Manifest Ego
| Stage | Manifest Ego | Effect |
|---|---|---|
| 1 | Sleeping Memory | Add Graveyard/Discard Pile to Joker card search range |
| 2 | Awakening Memory | Heal Cassius 40% each time he draws with ability |
| 3 | Vivid Memory | Increase Potential level +3 for [Upgrade Basic Cards], [Upgrade Neutral Cards], [Upgrade Unique Cards] |
| 4 | Inner Memory | Death Trick Morale Reduction +2 to all enemies (total -5) |
| 5 | Complete Memory | Increase Potential level +3 for [Upgrade Basic Cards], [Upgrade Neutral Cards], [Upgrade Unique Cards] |
| 6 | Liberated Memory | Quest completion: apply -1 Morale to all enemies for 1 turn |
How to Play Cassius in Chaos Zero Nightmare
Cassius's gameplay revolves around the Quest system, a unique mechanic where completing specific card-playing conditions generates powerful 0-cost Quest Cards. Understanding Quest mechanics, card manipulation tools, and how to leverage his card search is the most important aspect of playing Cassius. Unlike traditional supports who provide passive buffs, Cassius actively shapes the flow of battle by controlling what cards your team has access to, when they can use them, and how many resources they need to execute combos.
The core of Cassius's kit is Pop Eyed Popper, an Upgrade with Initiation that guarantees it appears in your opening hand. Using it starts one of four Quests, displayed below Cassius's health bar. Quests persist for the entire battle and can be completed multiple times. Each completion generates a Quest Card - a powerful 0-cost card with Ephemeral (exhausts after use). The four Quests are:
- Triple 0: Play 3 cards costing 0 AP. Generates Triple 0 (0-cost Attack: 40% damage per Attack card used this turn). This Quest is difficult for Cassius to complete alone since his cards naturally cost 1+ AP. However, it becomes explosive in teams with abundant 0-cost cards. Tressa's Shadow Daggers, Luke's Bullets, Mika's healing Skills, and discounted Neutral cards all count. In specialized Triple-0 builds with Tressa, you complete this Quest 5-10+ times per turn, accumulating multiple Triple 0 cards that deals a lot of damage!
- Triple 1: Play 3 cards costing 1 AP. Generates Triple 1 (0-cost Attack: 90% damage, 90% heal). The easiest Quest to complete consistently since most characters have abundant 1-cost cards. The reward is weak - the damage is modest and healing is rarely needed when running Mika - making this the least valuable Quest for endgame builds.
- Straight: Play cards costing 0, 1, and 2 AP (one of each). Generates Straight (0-cost Skill: 2 Morale, 2 Resolve, 2 Fortitude for 1 turn). This is the offensive buff Quest. Morale grants +40% damage (20% per stack), Resolve grants +40% shields, Fortitude grants +40% damage reduction. Completing Straight before your DPS takes their turn amplifies their burst significantly. The difficulty is reliably having 2-cost cards to trigger it.
- Full House: Each combatant (all 3 team members) plays 1 card. Generates Full House (0-cost Skill: Draw 1). This is the card draw Quest and the most universally valuable for general use. It's easy to complete - just ensure each team member plays at least one card per turn, which happens naturally. The free Draw 1 provides card advantage without resource investment. Full House is the default choice for teams that don't specifically build around Triple 0.
Quest Cards have Ephemeral, meaning they exhaust after use and don't return to your deck. You must use them the turn they're generated or lose them forever. The exception is Pop Eyed Popper II epiphany, which removes Ephemeral and adds Retain, letting you hold Quest Cards. For most builds, Ephemeral is fine - you want to use Quest Cards immediately for their effects.
The key decision is which Quest to start. Pop Eyed Popper base randomly selects one of four, which is high variance. Pop Eyed Popper IV is the optimal epiphany for consistency - it lets you choose which Quest to start. If your deck has abundant 0-cost cards, choose Triple 0. If you need buffs for burst turns, choose Straight. If you just want card draw, choose Full House. The ability to guarantee your Quest removes RNG and lets you build optimally.
Pop Eyed Popper I (Initiation, starts random Quest) is acceptable for Chaos runs where you adapt to what you're offered. Pop Eyed Popper III (creates stronger Quest Cards) is niche - "stronger" versions aren't dramatically better, making consistency more valuable than power.
After establishing your Quest, Cassius's role becomes using his card manipulation tools to complete Quests efficiently while enabling your main DPS. His three core cards are Devil Dice, Shuffle, and Joker.
Devil Dice is Cassius's primary cycling card. At base (Epiphany II), it costs 1 AP, deals 160% single-target damage, and draws 1 card. Simple but effective - it advances your turn by replacing itself with a new card while dealing damage to progress fights. The best epiphany is Devil Dice V, which reduces cost to 0 AP, changes it to AoE, and makes damage equal 80% of the drawn card's cost. This is incredible efficiency - 0 AP to deal AoE damage AND draw a card is free card advantage. If you draw a 2-cost card, it deals 160% AoE damage. Getting 0-cost on Devil Dice (either through Epiphany V or Divine Epiphany) is a priority.
Shuffle is Cassius's hand reset tool. Base version costs 1 AP, has Exhaust, discards your entire hand, then draws equal cards. This is your reset button - if you drew poorly and your hand doesn't support your strategy, Shuffle resets everything. Use it when your hand is actively bad (missing key cards, wrong costs for Quest, etc.), not just slightly suboptimal.
The best Shuffle epiphany is Shuffle III - it costs 1 AP, moves all cards from hand AND Discard Pile back into Draw Pile, shuffles everything, then draws 5. This is significantly stronger than base because it recycles your entire deck mid-battle. If your Draw Pile is empty and your hand is mediocre, Shuffle III puts everything back and gives you a fresh 5-card hand from the full deck.
Shuffle II (discard any number, draw equal) is more flexible but usually weaker than III's full reset. Shuffle IV (0-cost, select 5 cards from Discard to put on Draw Pile top) is strong for precise setups but requires planning. Shuffle V (draw 3, if total cost ≤4, discard them all) is unreliable.
Joker is Cassius's signature card and one of the strongest cards in the game. It costs 1 AP, lets you select any card from your Draw Pile and add it to hand. This is universal card search - you can look through your entire Draw Pile and pick exactly what you need. Need your DPS's finisher card? Joker it. Need Mika's AP generation? Joker it. Need a specific cost card to complete a Quest? Joker it. Joker has no Epiphany variants because base Joker is already perfect - it doesn't need upgrades.
At E0, Joker only searches Draw Pile. This has a major limitation - if your Draw Pile is empty (all cards in hand or Discard), Joker does nothing. At E1, Joker searches Draw Pile AND Discard Pile/Graveyard, making it twice as powerful by effectively searching your entire deck. E1 is mandatory for serious Cassius play - without it, Joker is situationally useless.
One critical Joker limitation: you cannot search for cards used this turn. When you play a card, it moves to "used this turn" limbo before going to Discard at turn end. Joker cannot access that limbo. This means you can't use a powerful card, then Joker to retrieve and use it again the same turn. You can only Joker cards that weren't played this turn. Plan accordingly.
Dice Trick is Cassius's scaling damage card. Base costs 2 AP, deals 360% single-target damage, and costs -1 AP for each Quest you've completed this battle. If you've completed 2 Quests, it costs 0 AP. The problem is Dice Trick starts expensive and requires Quest completions to become good, making it a mid-to-late turn card. Dice Trick I (AoE version) and III (0-cost but damage scales per Quest) are alternatives, but the standout epiphany is Dice Trick V.
Dice Trick V transforms from an Attack into an Upgrade that costs 2 AP and reads: "On Quest completion, create 1 Quest Card." This is the Quest multiplier - every time you complete a Quest, you generate an extra Quest Card beyond the one the Quest itself gives. In Triple-0 builds, Dice Trick V is mandatory.
Cassius's basic cards (Card, Wild Card, Mana Field) are weak and should be removed in optimized builds. They don't synergize with Quest mechanics, don't provide card draw, and Cassius doesn't need personal damage or healing when his role is enabling teammates. Potential 3-1 gives Card/Wild Card a 30% chance to draw, making them slightly less dead, but you'll still remove them. The only reason to keep Wild Card temporarily is if you need a 2-cost card to complete Straight Quest and have no better options.
A typical Cassius turn follows this pattern: Start turn → Check hand → Use Joker to search for key cards → Use Devil Dice to cycle → Complete Quest requirements → Use generated Quest Cards → Advance main DPS combo. The order matters - always draw/search first to maximize information before committing resources. Complete Quests as early in turn as possible (especially Straight) to benefit from buffs that last "for 1 turn" during your actual damage cards.
Straight Quest is optimal for burst-focused teams. If your DPS needs Morale buffs for a big turn (Renoa's Durge Bullets, Kayron's Black Hole), complete Straight at turn start (+40% damage), then execute the combo. Straight completion also triggers Potential 7 for an additional Morale stack, totaling 3 Morale (+60% damage).
Teams with Luke work similarly to Tressa for Triple-0 completion. Luke generates many 1-cost Handgun Bullets that can be discounted to 0-cost through various effects. Once you have 3 0-cost Bullets in hand, complete Triple-0 repeatedly. Luke also benefits from Cassius's card draw to find his Last Stitch Assault finisher faster.
Cassius's Death Trick Ego Skill costs 4 EP and is primarily defensive. The -3 Morale debuff (-60% enemy damage, -100% with E4) is devastating against multi-hit attacks. Enemies with Consecutive Attacks that hit 5 times normally deal massive damage - with -3 Morale, each hit is reduced by 60%, often resulting in chip damage. Use Death Trick when facing enemies with high offensive output or preparing for a major enemy attack turn. The 2 random Quest Cards generated are bonuses - activate Death Trick at turn start so you can plan around which Quest Cards you receive.
Cassius's greatest strength is versatility. He fits into virtually any team because card draw and card search are universally valuable. His greatest weakness is setup dependency - he requires specific Epiphanies (Pop Eyed Popper IV, Devil Dice V, Dice Trick V, Shuffle III) to reach peak performance. He's also AP-hungry - 1 AP for Joker, 1 AP for Devil Dice, 1 AP for Shuffle adds up quickly, requiring AP generation from teammates (Mika's Source of Water, Neutral cards like Glorious Resistance).
When mastered, Cassius transforms from a simple support into a combo enabler, damage amplifier, defensive tool, and in Triple-0 builds, a primary damage dealer. His skill ceiling is among the highest in the game - perfect play requires tracking Quest progress, knowing your entire team's deck composition, predicting which cards to search with Joker, timing Quest completions for maximum buff value, and managing hand size (max 10 cards) during explosive turns. The reward for this mastery is one of the most powerful characters in Chaos Zero Nightmare.
