CASTORICE
Goddess of Death Build Guide
SS TIER DPSServant of Death
Castorice is a groundbreaking 5-star Quantum Remembrance character who commands the battlefield through her formidable Memosprite, Netherwing: Pollux. As the daughter of the River of Souls and a Chrysos Heir seeking the “Death” Coreflame, Castorice wields a unique HP-manipulation mechanic that transforms ally sacrifices into devastating AoE Quantum damage.
Her gameplay revolves around accumulating “Newbud” through team HP loss and healing, which fuels her Ultimate to summon Netherwing. Once deployed, Netherwing creates the Lost Netherland Territory, reducing all enemies’ All-Type RES by 20% while unleashing repeated Quantum strikes. Castorice excels in Pure Fiction and multi-target scenarios, making her one of the most powerful AoE DPS units in Version 4.0.
Global Passive Bonus: For the first time in Honkai: Star Rail, Castorice introduces a revolutionary global passive that affects your entire account. Even when not in your active team, she grants all parties a one-time resurrection per battle—fallen allies return with 1 HP and can be saved with healing or shields. This passive works even in endgame modes!
Best Light Cones
Make Farewells More Beautiful
⭐⭐⭐⭐⭐ SignatureBest-in-Slot: Castorice’s signature Light Cone that perfectly synergizes with her HP-based kit. Increases Max HP by 30-60% and grants “Death Flower” when Castorice or Netherwing loses HP, allowing them to ignore 24-30% of enemy DEF for 2 turns. Additionally advances Castorice’s action by 12-24% when Netherwing disappears, ensuring smooth rotation cycles. This is her undisputed best weapon.
The Flower Remembers
⭐⭐⭐⭐ Battle PassPremium 4-Star: Excellent Battle Pass alternative that provides substantial ATK% and HP% bonuses. When the wearer or their Memosprite uses Skill, increases DMG dealt. Works remarkably well for Castorice’s constant Skill usage and significantly cheaper to obtain than her signature.
Sweat Now, Cry Less
⭐⭐⭐⭐ Battle PassAlternative Battle Pass: Another viable Battle Pass option that boosts Energy Regeneration Rate and provides healing plus ATK buffs when allies use Ultimates. Helps sustain the HP-draining team while enhancing damage output.
High Base HP Light Cones
⭐⭐⭐⭐⭐ Stat StickF2P Fallback: Any 5-star Remembrance Light Cone with high base HP can serve as a temporary option. While their effects won’t activate optimally for Castorice, the base HP stat still provides value since her damage scales with Max HP. Examples include other Remembrance path cones you might have.
Light Cone Priority
Investment Recommendation: Castorice’s signature Light Cone is highly recommended. The Battle Pass options (The Flower Remembers or Sweat Now, Cry Less) are solid mid-tier alternatives that perform 70-80% as well. Unlike some characters, Castorice has limited F2P options, making the Battle Pass or signature essential for optimal performance.
Best Relic Sets
Poet of Mourning Collapse (4-Piece)
BEST-IN-SLOT RELIC SET
Why It’s Perfect: Custom-designed for Castorice. The low SPD requirement synergizes perfectly with her playstyle—build her with minimal speed and let the set grant 88% CRIT Rate (8% + 40% + 40%) after using Ultimate! This allows you to focus entirely on CRIT DMG and HP substats. Both Castorice and Netherwing benefit from these CRIT Rate buffs.
Alternative: Mixed 2-Piece Sets
TEMPORARY OPTION
Why It Works: If you haven’t farmed Poet yet, combining two 2-piece sets provides decent stats. Both bonuses apply to Netherwing, making this a serviceable transitional build. However, you should prioritize farming Poet of Mourning Collapse as soon as possible.
Planar Ornaments
Bone Collection’s Serene Demesne
BEST-IN-SLOT ORNAMENT
Why It’s Perfect: Tailor-made for Castorice. Reaching 5000 HP is trivial with her HP scaling, and the 28% CRIT DMG boost applies to both Castorice and Netherwing. The Max HP bonus also directly increases her damage multipliers. This is her undisputed best ornament.
Izumo Gensei and Takama Divine Realm
ALTERNATIVE OPTION
Why It Works: Provides team-wide CRIT Rate support while boosting Castorice’s ATK. However, since Poet already gives abundant CRIT Rate, this ornament is less valuable. Only use if you lack Bone Collection.
Optimal Main Stats & Sub-Stats
Main Stats Priority
Always use CRIT DMG Body since Poet set provides 88% CRIT Rate
HP% preferred for better scaling; ATK% if HP is already high
HP% generally better due to multi-target damage distribution
Essential for maximizing damage multipliers
Target Stats
Stats Optimization Tips
CRITICAL: Keep SPD at 100 or Below! The 4-piece Poet bonus requires 100 or lower SPD for the additional 40% CRIT Rate. Build her intentionally slow—this is NOT a mistake, it’s optimal! Action advance from supports will move her anyway.
CRIT Rate Abundance: With Poet (88% CRIT Rate after Ultimate), you only need 7-12% from substats to reach 95-100% total. This lets you stack CRIT DMG, HP%, and ATK% aggressively.
Sub-Stats Focus: CRIT DMG > HP% > ATK% > CRIT Rate (if under 95%). Avoid SPD substats entirely—they actively hurt your build by potentially pushing you above 100 SPD.
Best Team Compositions
❄️ Premium Remembrance Core (Best Team)
The Ultimate Castorice Setup: This is Castorice’s absolute best team composition. Tribbie provides All-Type RES PEN with her Skill, increases enemy DMG taken with her Ultimate, and contributes follow-up attacks for additional damage. Her high HP pool synergizes perfectly with Castorice’s Newbud generation.
Remembrance Trailblazer summons Mem, which grants CRIT DMG buffs and True DMG with “Mem’s Support” when advancing Castorice’s action. The True DMG procs repeatedly during Netherwing’s multi-hit attacks, dramatically amplifying total damage output. This free character is essential for Castorice teams.
Luocha is the ideal healer—his field provides automatic healing when allies attack, which uniquely allows Netherwing to heal during its first “Breath Scorches the Shadow” cast. This enables using 4 charges instead of 3, maximizing Netherwing’s damage window.
Why It Dominates: Perfect synergy between HP manipulation, healing conversion to Newbud, True DMG amplification, and RES penetration. Can clear all Pure Fiction stages with maximum scores and excels in Memory of Chaos AoE scenarios.
🌙 Advanced Remembrance (With Sunday)
Premium Buff Stacking: Replace Tribbie with Sunday for an alternative high-damage approach. Sunday’s Ultimate grants massive CRIT DMG buffs to both Castorice and Netherwing (transformed into “The Beatified”), while his Skill provides action advance. The energy restoration from Sunday also generates Newbud.
This team trades some of Tribbie’s RES penetration for significantly higher CRIT DMG scaling, making it better against tanky enemies with moderate resistances. Sunday’s buffs last long enough to cover most of Netherwing’s active turns.
When to Use: Boss fights, Apocalyptic Shadow, and scenarios where maximizing single rotation burst damage is more important than sustained AoE pressure. Sunday’s SP-neutral nature with his signature Light Cone helps team economy.
⚡ F2P Excellence
Highly Accessible Powerhouse: Remarkably effective team using mostly free or easily accessible characters. Remembrance TB (free) provides essential CRIT DMG and True DMG support. Ruan Mei offers All-Type RES PEN, DMG%, and SPD buffs—her SPD bonus won’t break Poet’s 4-piece bonus if you keep Castorice at 95 base SPD.
Gallagher (free from version rewards) is the best F2P sustain for Castorice. His Ultimate increases Break DMG taken while providing team-wide healing through Besotted state. He’s SP-positive, generates excellent Newbud through HP restoration, and his frequent attacks proc useful effects.
Budget-Friendly Power: Perfect for new players or those saving resources. Despite being F2P-friendly, this team comfortably clears all endgame content with proper builds. Highly recommended starting point for Castorice players.
💎 Future-Proof Remembrance (3.3+)
Next-Generation Setup: Evernight and Cyrene (releasing in Version 3.7) provide specialized Remembrance path buffs that significantly amplify Memosprite damage. Cyrene in particular synergizes with the full Remembrance lineup, boosting all summon-related effects.
Hyacine (Version 3.3) is the first Remembrance path healer, making her incredibly valuable for Castorice. She heals both herself and through her Memosprite “Little Ica,” breaking the limitation of no Remembrance healers. Her high SPD increases healing amounts when speed-tuned properly. Little Ica also consumes HP, building Newbud faster than any other sustain.
Investment Timeline: Wait for Version 3.3 and 3.7 releases before committing resources. This team represents the theoretical peak of Remembrance synergy but requires significant pulls. Monitor announcements and community testing.
🎯 DEF Shred Variant
Defense Reduction Focus: Pela reduces enemy DEF significantly with her Ultimate (up to 40%), increasing Castorice’s overall damage output. She’s SP-positive, making team economy easier. This compensates for not having Tribbie’s RES penetration through direct DEF shred instead.
Works best against high-DEF enemies like tanky elites and bosses. Pela’s debuff applies to all enemies, synergizing with Castorice’s AoE focus. The free slot for sustain allows flexibility—use Gallagher for budget or Luocha for premium healing.
When to Use: Excellent option if you lack Tribbie but need strong support. Pela is a free 4-star from various sources and performs admirably. This team bridges the gap between F2P and premium compositions effectively.
🔥 Dual DPS (Advanced)
HP Synergy Duo: Mydei (Imaginary Destruction) or Blade (Wind Destruction) both consume their own HP for damage, creating constant Newbud generation for Castorice. Mydei accumulates Charge from HP loss to enter “Vendetta” state, while Blade’s kit revolves around self-HP consumption.
This creates a unique dynamic where both DPS units fuel each other—Castorice drains team HP for Newbud while simultaneously feeding Mydei’s Vendetta or Blade’s damage scaling. The constant HP flux requires strong healing from Luocha.
Risk vs Reward: Deals incredible damage when properly executed but demands precise HP management. Less consistent than single-DPS teams but offers peak damage potential. Recommended only for experienced players comfortable with aggressive HP manipulation.
Team Building Guidelines
Healer Priority: Luocha > Hyacine (3.3+) > Gallagher > Lingsha. Castorice uniquely benefits from healers that restore HP frequently since healing converts to Newbud (A2 Trace). Luocha’s field healing during attacks is irreplaceable.
Support Synergy: Action advance (Sunday, RMC) + RES penetration (Tribbie, Ruan Mei) creates optimal conditions. Avoid shields—they conflict with Castorice’s HP manipulation and provide no Newbud generation.
Speed Tuning: Keep Castorice at 95-100 SPD always. Supports should be 140-160 SPD to advance her frequently while maintaining buff uptime. Never sacrifice the Poet 4-piece bonus for speed.
Remembrance TB Essential: This free character is mandatory for Castorice teams. The True DMG from Mem’s Support amplifies her damage by 30-40% alone. Always include RMC in your composition.
Trace Priority & Leveling Order
Leveling Priority
-
Ultimate (Highest Priority)
Level this FIRST to 10. Summons Netherwing and creates Lost Netherland Territory. The RES reduction increases with levels (10% → 20%), dramatically improving both Castorice’s and Netherwing’s damage. This is her most impactful trace. -
Talent (Second Priority)
Level to 10 after Ultimate. Governs Newbud generation and DMG% stacking (10% → 20% per stack, max 3 stacks). Also controls Netherwing’s HP inheritance and healing mechanics. Essential for energy cycling. -
Skill (Third Priority)
Level to 10 next. Increases both normal Skill and enhanced “Boneclaw, Doomdrake’s Embrace” damage multipliers. Improves both HP drain efficiency and direct damage output. Important but less impactful than Ultimate/Talent. -
Basic ATK (Lowest Priority)
Level last to 6-8 (optional 10 if resources permit). HP-scaling Basic ATK that does decent damage but doesn’t generate Newbud. Rarely used in optimal rotations. Save materials by keeping this at lower levels.
Major Traces (Unlock All – Critical!)
Contained Dark Tide (A2) – ESSENTIAL
Most Important Trace: After ally targets (excluding Netherwing) receive healing, converts 100% of healed amount into Newbud. If Netherwing is active, converts to Netherwing HP instead. Each ally can accumulate up to 12% of max Newbud capacity per action cycle.
This trace is MANDATORY—it enables healing-to-Newbud conversion, drastically accelerating Ultimate rotations. Without this, Castorice’s energy generation is crippled. Coordinate heals right before Castorice’s turn to maximize efficiency.
Inverted Torch (A4)
Increases Castorice’s SPD by 40% when her HP is 50% or higher. When Netherwing uses “Breath Scorches the Shadow” and deals fatal damage or reduces enemy HP to minimum, Netherwing gains 100% SPD for 1 turn.
Helps maintain action economy despite low base SPD. The conditional SPD boost keeps Castorice from being too slow, while Netherwing’s SPD increase maximizes its damage window before disappearing.
Where The West Wind Dwells (A6)
Enhances Netherwing’s “Breath Scorches the Shadow” by increasing its damage multiplier by 30% each cast, stacking up to 6 times until turn ends. This ramps Netherwing’s damage from 12% → 14% → 17% multipliers (of Castorice’s Max HP) per repeated cast.
Transforms Netherwing into a devastating damage dealer. By the 3rd-4th cast, multipliers reach maximum, allowing Netherwing to delete entire enemy waves. Makes spamming “Breath Scorches the Shadow” the optimal strategy.
Resource Management
Optimal Path: Max Ultimate first (RES shred), then Talent (Newbud/DMG%), then Skill (damage multipliers), finally Basic ATK (filler). All Major Traces MUST be unlocked immediately—they’re not optional!
A2 Trace Priority: Contained Dark Tide (healing-to-Newbud) is absolutely essential. This trace alone determines whether Castorice functions smoothly or struggles. Unlock this before even leveling abilities if resources are tight.
Gameplay Guide & Mechanics
Understanding Newbud System
Castorice uses a unique energy mechanic called “Newbud” instead of traditional energy:
- Gains 1 Newbud for every 1 HP lost by allies (except Netherwing)
- Gains 1 Newbud per 1 HP healed to allies (A2 Trace – capped at 12% max Newbud per target per action)
- Maximum Newbud capacity: 34,000 at Equilibrium Level 6
- When Newbud reaches maximum, Ultimate can be activated
- Gains 10-20% DMG increase per ally HP loss stack (max 3 stacks, 60% total DMG boost)
- When Netherwing is active, cannot gain Newbud—all mechanics convert to Netherwing HP instead
- Starts with 30% Newbud when entering battle without Technique (10,200 Newbud)
Netherwing: Pollux Mechanics
When Ultimate Activates:
- Territory Deployment: Creates “Lost Netherland” reducing all enemies’ All-Type RES by 10-20%
- Immediate Summon: Netherwing spawns with action advanced 100%
- HP Pool: Netherwing Max HP equals max Newbud (34,000 HP at EL6)
- Fixed SPD: Netherwing has 165 SPD and acts independently
- Limited Duration: Disappears after 3 turns OR when HP reaches 0
- Two Attack Options:
- “Claw Splits the Veil” – AoE damage (40% of Castorice’s Max HP), ends turn immediately
- “Breath Scorches the Shadow” – Consumes 25% Netherwing HP, deals AoE damage with escalating multipliers (12% → 14% → 17% of Castorice’s Max HP), can be cast repeatedly in single turn
- Detonation: When disappearing, “Wings Sweep the Ruins” deals 6 bouncing hits (20% Max HP each) and restores team HP
Optimal Rotation Strategy
Pre-Battle (Always Use Technique!):
- Activate Castorice’s Technique for “Netherveil” (enemies can’t approach)
- Enter battle with Netherwing pre-summoned at 50% HP
- Technique drains 40% team HP, immediately healing Netherwing to ~full
- This allows immediate Netherwing usage on turn 1!
Opening Turn (With Technique Start):
- Remembrance TB uses Skill on Castorice (CRIT DMG buff, True DMG enabled)
- Support (Tribbie/Sunday) buffs Castorice
- Netherwing immediately spams “Breath Scorches the Shadow” 3-4 times
- First cast: 12% multiplier
- Second cast: 14% multiplier
- Third+ cast: 17% multiplier (max)
- With Luocha field: Can cast 4 times due to healing between first casts
- Detonate Netherwing immediately (fast cycle strategy)
Subsequent Rotations:
- Castorice uses Skill (drains 30% team HP when solo, 40% with Netherwing)
- Healer restores HP (converts to Newbud via A2 Trace)
- Repeat Skill usage and healing until Newbud reaches maximum
- Apply all support buffs right before Ultimate
- Ultimate → Netherwing spam → Detonate → Repeat
Advanced Tip: There are two viable playstyles: (1) Instant detonation for fast cycling and frequent Newbud generation, or (2) Keeping Netherwing alive 2-3 turns for sustained damage. Fast cycle is generally superior for Pure Fiction, while sustained works better for bosses.
Technique Usage
ALWAYS Start With Technique When Possible:
- Prevents enemy aggro during exploration (enemies can’t approach)
- Summons Netherwing immediately at battle start (50% HP + 40% team drain = near full HP)
- Enables turn 1 Netherwing attacks without waiting for Ultimate
- Generates initial 30% Newbud if you choose NOT to use Technique
Decision Point: Technique start is almost always superior. Only skip if you need the 30% starting Newbud for some reason, but this is rare. The ability to attack immediately with Netherwing far outweighs delayed Newbud accumulation.
HP Management Principles
Balancing Drain and Healing:
- Castorice’s Skill drains 30-40% current HP, not max HP—safer than it sounds
- Cannot reduce ally HP below 1 (built-in safety)
- Healing immediately converts to Newbud (1:1 ratio up to 12% cap per target)
- Time healer actions right before Castorice’s turn for maximum efficiency
- High HP pools (Tribbie, HP% builds) generate more total Newbud per cycle
- Shields provide no value—they don’t generate Newbud and block healing conversion
Common Mistakes to Avoid
❌ Don’t forget to use Technique—starting without Netherwing wastes turn 1 potential
❌ Don’t build SPD above 100—you’ll lose the crucial 40% CRIT Rate from Poet
❌ Don’t use “Claw Splits the Veil” when “Breath Scorches the Shadow” is available
❌ Don’t forget Remembrance TB’s Skill—True DMG multiplies Netherwing’s multi-hit attacks
✅ Do spam “Breath Scorches the Shadow” repeatedly for ramping damage (A6 Trace)
✅ Do coordinate healing right before Castorice’s turn for optimal Newbud conversion
✅ Do prioritize HP% on relics—it scales both damage and Newbud pool
Eidolon Guide
Eidolon Priority & Value
E0 (Base): Already exceptionally powerful and complete. Castorice is fully functional at E0 and clears all endgame content comfortably. F2P players should stop here—no eidolons are necessary.
E1: After Netherwing uses Ultimate or Enhanced Skill, immediately restores 30% Ultimate charge and grants 1 additional enhanced action. Quality-of-life improvement that accelerates rotations and allows extra Netherwing casts. Nice but not essential. Value: 15-20% overall DPS increase.
E2 (Major Breakpoint): Increases Ultimate and Talent DMG by 50%. This is the BEST stopping point for spenders—massive damage spike that affects both Castorice’s direct damage and Netherwing’s output. Transforms her from top-tier to absolutely dominant. Value: 40-50% overall DPS increase over E0.
E4: Lost Netherland Territory also reduces enemies’ DEF by 30% and increases action limit by 1 turn. Extends Netherwing’s presence and adds substantial DEF shred. Good power spike but E2 is more impactful. Value: 20-25% DPS increase over E2.
E6: Multiple buffs including increased final detonation damage, SPD boosts, and CRIT DMG increases. Whale territory only—provides incremental benefits over E4. Makes Castorice absolutely broken but astronomically expensive. Value: 30-35% DPS increase over E4.
Investment Recommendation: E0 is perfect for most players. If spending, E2 provides exceptional value as it nearly doubles her damage output. E4 and E6 are luxury upgrades for dedicated fans or whales. The jump from E0 → E2 is more valuable than E2 → E6.
Pull Priority: Light Cone vs Eidolons
For Most Players: E0S1 (Character + Signature Light Cone) > E1S0. The signature Light Cone provides more consistent power than E1 and is essential for optimal performance.
F2P Focused: E0S0 with Battle Pass Light Cone (The Flower Remembers) is viable for all content. Save pulls for other characters.
Dolphins: E0S1 offers best value. Alternatively, E2S0 if you have Battle Pass Light Cone.
Whales: E2S1 is the optimal stopping point for power-to-investment ratio. Beyond E2, returns diminish significantly.
Strengths & Weaknesses
❄️ Strengths
- Exceptional AoE Damage: Dominates Pure Fiction and multi-target scenarios with repeated Netherwing attacks
- Global Passive: Revolutionary account-wide resurrection mechanic that works in ALL content
- F2P Friendly Teams: Strong with Remembrance TB (free), Gallagher (free), and Ruan Mei (accessible)
- Unique HP Mechanics: Turns HP drain into strength—only character that benefits from both damage AND healing
- Territory Control: Lost Netherland’s 20% RES reduction benefits entire team, not just Castorice
- Flexible Playstyles: Can burst with instant detonation or sustain damage through extended Netherwing presence
- No SPD Requirements: Actually BENEFITS from low speed due to Poet set, simplifying gearing
- Future-Proof: Remembrance path continues to receive support through new characters
⚠️ Weaknesses
- Light Cone Dependent: Limited F2P options—Battle Pass or signature strongly recommended
- Relic Farming Required: Poet of Mourning Collapse is mandatory; alternatives perform 30-40% worse
- HP Management Complexity: Requires understanding of drain-heal timing and Newbud caps
- Healer Specific: Performs best with frequent healers (Luocha, Gallagher); struggles with burst healers
- Shield Anti-Synergy: Shields completely conflict with her kit—avoid sustain like Aventurine
- Single-Target Limitations: While decent, not her specialty—Phainon and Feixiao are better for bosses
- Newbud Accumulation: First Ultimate takes setup time without Technique start
- Territory Exclusivity: Only one Territory can exist at a time—conflicts with other Territory users
Meta Position & Character Comparison
Castorice vs Other Top DPS
vs Phainon (Physical Destruction): Phainon excels in single-target burst and Apocalyptic Shadow. Castorice dominates Pure Fiction and AoE scenarios. Different niches—both are SS tier. Phainon is more self-sufficient; Castorice requires healer support. Both benefit from Remembrance teams.
vs The Herta (Ice Erudition): Direct competition for Pure Fiction supremacy. The Herta has easier team building and simpler execution. Castorice has higher damage ceiling with proper setup and HP manipulation. The Herta is more consistent; Castorice has higher peaks. Both are Pure Fiction specialists.
vs Feixiao (Wind Hunt): Feixiao offers consistent follow-up attack damage and flexible team building. Castorice provides devastating burst AoE but needs specific support. Feixiao is SP-positive and easier to play; Castorice has higher AoE potential. Different damage patterns—Feixiao for consistency, Castorice for explosions.
vs Acheron (Lightning Nihility): Acheron has superior single-target and versatile teams. Castorice wins in Pure Fiction AoE scenarios. Acheron’s debuff-stacking is more flexible than Castorice’s HP manipulation. Both are top-tier but optimized for different content—Acheron for MoC/AS, Castorice for PF.
Should You Pull Castorice?
✅ Pull if:
- You need a Pure Fiction specialist (she’s THE best for this mode)
- You own Remembrance TB, Tribbie, or strong Remembrance supports
- You have Battle Pass access or can get her signature Light Cone
- You want the global resurrection passive (works account-wide!)
- You enjoy unique HP manipulation mechanics and strategic gameplay
- You lack strong AoE DPS options
⚠️ Consider Skipping if:
- You already have The Herta and strong Pure Fiction clearers
- You cannot obtain Battle Pass or signature Light Cone
- You lack Luocha, Gallagher, or suitable healers
- You prefer simple, straightforward DPS characters
- You’re saving for upcoming Remembrance supports (Hyacine, Cyrene)
- You primarily focus on single-target content like Apocalyptic Shadow
Final Verdict: Castorice is an exceptional limited 5-star that redefines AoE damage and introduces revolutionary account-wide mechanics. She’s a safe pull for players lacking Pure Fiction specialists and offers unique gameplay that rewards mastery. Her global passive alone provides value even when benched. Rated SS tier for excellent reason—one of the strongest and most innovative releases in HSR 4.0. While she requires specific supports and Light Cones, her power ceiling justifies the investment.