Castorice Build Guide HSR 4.3 – Best Relics, Light Cones, Teams & Eidolons

• Castorice is a 5-star Quantum Remembrance DPS who summons a memosprite called Netherwing to deal massive AoE damage.
• She scales entirely off Max HP — ATK is completely useless on her. Build HP first, then CRIT stats.
• She charges her Ultimate through Newbud, a resource gained when allies lose HP — not from Energy.
• Best Light Cone: Make Farewells More Beautiful (her signature). The gap between this and alternatives is large.
• Best Relics: Poet of Mourning Collapse (4-piece) + Bone Collection’s Serene Demesne (Planar Ornament).
• Best team: Castorice / Evernight / Cyrene / Hyacine. Strong F2P alternative with Trailblazer (Remembrance) + Tribbie + Hyacine.
• Never use shielders on her team — shields intercept HP drain and completely break her Newbud generation.
• E2 is her biggest power spike and the recommended investment stop point for dedicated players.
• Castorice is rated T0 in Memory of Chaos, Pure Fiction, and Apocalyptic Shadow as of patch 4.3.

Who Is Castorice in Honkai Star Rail?

Castorice is a 5-star Quantum character following the Path of Remembrance in Honkai Star Rail. She debuted in Version 3.2 and has remained one of the strongest and most consistently rated DPS characters in the game ever since. As of patch 4.3, she sits at T0 across all three main endgame modes — Memory of Chaos, Pure Fiction, and Apocalyptic Shadow — making her arguably the most well-rounded carry in the current roster.

In the game’s story, Castorice is the daughter of the River of Souls, a Chrysos Heir searching for the Coreflame of “Death.” She hails from Aidonia, a snow-covered land that reveres death, and her journey is shaped by a heavy burden: guarding the lament of souls and accepting the solitude that comes with her destiny. The game describes her beautifully — “Life and death are but a journey. When the butterfly alights on the branch, what withers will bloom anew.”

What makes her fascinating to play is how deeply her lore connects to her gameplay. Her kit literally revolves around draining the life force of her allies to fuel a resurrection-like transformation. She also has a unique global passive that revives a fallen ally once per battle — a first for Honkai Star Rail.

Her most recent rerun was in Version 4.2 (April 21 – May 13, 2026) via the Indelible Coterie banner alongside The Dahlia and Firefly. Keep an eye on future banner announcements for her next opportunity. This guide covers everything you need to maximize Castorice in the current 4.3 meta.

Castorice Kit Overview – How Her Abilities Work

Castorice’s kit is built around one core loop: drain your team’s HP to generate Newbud, then spend Newbud to summon Netherwing and deal enormous AoE Quantum DMG. Every single ability ties back to this loop. Understanding it is essential before looking at builds.

Newbud – The Core Resource

Newbud replaces the standard Energy system for Castorice. For every point of HP lost by any ally (including Castorice herself), she gains 1 point of Newbud. When Newbud reaches maximum capacity, she can use her Ultimate to summon Netherwing. The maximum Newbud value scales based on the combined character levels of all four team members.

Her A2 Major Trace also converts healing received by allies into Newbud. After any ally is healed, 100% of the healed HP value is converted into Newbud points, capped at 12% of Newbud’s maximum per target per action cycle. This is why high-throughput healers like Hyacine are so valuable — every heal tick feeds both Newbud generation and Netherwing sustain simultaneously.

Basic Attack – Pale Wings, Shaded Trail

Deals AoE Quantum DMG to all enemies based on Castorice’s Max HP. Unlike most basic attacks, this hits all enemies from the start, which helps break Toughness bars across the board. All damage scales with Max HP — your ATK stat contributes nothing here.

Skill – Butterfly on the River Styx

Consumes 30% of all allies’ current HP and deals Quantum Blast DMG based on Castorice’s Max HP. If Netherwing is already on the field, the Skill instead triggers a joint attack with Netherwing — AoE Quantum DMG to all enemies while consuming 40% of allies’ current HP. This Skill costs 0 SP. Castorice is completely SP neutral, freeing up Skill Points for teammates throughout the entire fight.

The HP drain targets current HP, not Max HP, so teammates cannot be killed by it. They simply lose a large chunk of their health bar, which gets topped back up by your healer. This constant drain is what feeds Newbud and keeps the loop going.

Ultimate – The Pale Lady Comes: Netherwing

When Newbud is full, Castorice summons the memosprite Netherwing. Netherwing advances its action by 100% and immediately enters the field. It creates the Territory “Lost Netherland,” decreasing all enemies’ All-Type RES by 20–25%. Netherwing has an initial SPD of 165 and Max HP equal to 100% of Castorice’s maximum Newbud value. After Netherwing acts for 3 turns or when its HP reaches 0, it disappears and the Territory is dispelled.

While Netherwing is active, Castorice can no longer generate Newbud through HP drain. Instead, all HP lost by allies is converted into HP restoration for Netherwing, keeping it alive longer. Netherwing deals Quantum DMG with all its moves, and all multipliers scale with Castorice’s Max HP.

Talent – Shadow Follows Light

When allies lose HP, Castorice and Netherwing both gain a 20% DMG increase. This stacks up to 3 times and lasts for 3 turns. In practice, the constant HP drain from Castorice’s Skill keeps a near-permanent 60% DMG buff active during combat. This is why maintaining consistent HP drain every rotation matters so much.

Global Passive – Once Per Battle Revival

Castorice has a global passive that functions as a one-time emergency revive. When any ally is knocked down, this passive triggers and revives them at 1 HP. It can only activate once per battle but applies to any ally, making it a genuine safety net in tough endgame content — especially when running triple-buffer setups without dedicated healing.

Technique – Netherveil

Using her Technique before a fight summons Netherwing immediately at battle start with 50% HP, drains 40% of all allies’ current HP, and grants Castorice 30% Newbud pre-loaded. Always use this before entering fights. The free Netherwing spawn and pre-loaded Newbud dramatically accelerate the first rotation cycle.

Castorice Best Light Cones in HSR 4.3

Castorice follows the Path of Remembrance. Only Remembrance path Light Cones trigger their passive effects on her. Since this path is newer with a smaller pool, alternatives are more limited compared to older paths.

Make Farewells More Beautiful (Signature – Best in Slot)

This is Castorice’s 5-star signature Light Cone and no alternative comes close. It provides a 30% Max HP increase — scaling all of her ability multipliers directly. It also grants 30% DEF Ignore for both Castorice and Netherwing, a multiplicative damage boost that stacks with RES PEN and vulnerability debuffs. Finally, it grants action advance when Netherwing exits the field, improving rotation timing. The power gap between this and alternatives is larger than most 5-star signatures in the game. If you’re pulling Castorice, strongly consider adding the signature.

Sweat Now, Cry Less (Battle Pass – Strong Alternative)

The best non-signature option at high Superimpositions. It provides CRIT DMG for Castorice that is inherited by Netherwing, plus an additional CRIT DMG buff specifically for Netherwing’s attacks. At high stacks, this delivers a meaningful damage contribution. If you have Battle Pass access, prioritize getting this to S5.

Time Waits for No One (5-Star Standard)

A 5-star standard Light Cone that grants a large Max HP bonus and HP-based healing value. The Max HP increase directly boosts Castorice’s damage multipliers. Usable if you have it from the standard banner or selector, but clearly below the signature in practice.

Off-Path High-HP Light Cones (Budget Option)

Since the Remembrance pool lacks strong F2P DPS options, running an off-path Light Cone purely for its base HP stat is a competitive budget choice. Look for any Light Cone with a base HP around 1164–1376 at max level. You lose the passive bonus, but the raw HP still boosts all her multipliers. Check your inventory before farming — you may already have something workable.

Castorice Best Relics in HSR 4.3

Castorice’s relic setup follows one core rule: all her damage scales with Max HP. Never prioritize ATK on her gear. Every piece should push toward Max HP first, then CRIT stats. ATK% and flat ATK rolls are completely wasted.

Best 4-Piece Relic Set: Poet of Mourning Collapse

This is Castorice’s best relic set by a wide margin. The 2-piece bonus provides CRIT Rate to help reach her in-combat breakpoints. The 4-piece is the critical piece — it unlocks maximum effects that supercharge her HP-scaling kit and directly boosts both Castorice and Netherwing’s performance. Always farm this set. Do not settle for alternatives unless you are transitioning while actively farming Poet of Mourning pieces.

Alternative: Iron Cavalry Against the Scourge

A temporary substitute if you have excellent substat rolls here. The Break-focused bonuses have limited value on Castorice, but solid substats can hold you over while targeting Poet of Mourning pieces. Not recommended as a long-term choice.

Best Planar Ornament: Bone Collection’s Serene Demesne

Castorice’s best Planar Ornament. It increases Max HP%, which scales all her damage multipliers directly, and provides bonuses that synergize with her HP drain mechanics. This is the ornament set to target first when farming Simulated Universe.

Alternative Planar Ornament: Penacony, Land of the Dreams

A decent backup that provides a DMG bonus against enemies affected by the same Quantum debuff as the wearer. Has some value in Quantum-heavy team setups. Use this if you have excellent substats here but poor Bone Collection pieces.

Relic Main Stats to Target

• Head: HP (fixed)
• Hands: ATK (fixed — the slot is locked, nothing to do here)
• Body: CRIT Rate
• Feet: SPD (aim for 134+ base)
• Planar Sphere: HP% if below 8,500 total HP; Quantum DMG Bonus if above 8,500 HP
• Link Rope: HP%

Substat Priority

HP% first. Then CRIT Rate to approach ~100% in-combat (including team buff contributions). Then CRIT DMG. SPD substats help cycle rotations faster and are worth picking up after the core offensive stats are solid. Skip ATK% and flat ATK entirely.

Stat Targets

• HP: 7,000+ out of battle (8,500+ preferred to unlock Quantum DMG sphere)
• CRIT Rate: ~100% in-combat
• CRIT DMG: 200%+
• SPD: 134+ base

Castorice Best Teams in HSR 4.3

Two hard rules apply to every Castorice team before anything else:

• Never use shielders. Characters like Aventurine, Fu Xuan, or Gepard generate shields that intercept HP drain before it generates Newbud. This breaks her kit entirely. Castorice can never fill her Newbud meter when shields absorb the damage.
• Always run direct healers. Characters that restore HP directly — like Hyacine, Luocha, or Gallagher — are the correct sustain options. The healing also feeds her A2 Trace for bonus Newbud.

Premium Team: Castorice / Evernight / Cyrene / Hyacine

This is Castorice’s best team in the current 4.3 meta according to community build trackers. Evernight is a Remembrance DPS who provides over 100 CRIT DMG to Netherwing, team-wide 30% All-Type RES PEN from her A6 Trace, and generates Memoria through HP loss events that sync perfectly with Castorice’s drain mechanic. Cyrene adds True DMG amplification and unique buffs that multiply with the team’s existing output. Hyacine is the ideal healer — she heals all allies, buffs Max HP for the full team, and her memosprite Little Ica triggers its own HP drain that generates Newbud through both the drain and the subsequent healing. Everything in this team feeds into everything else.

Strong Team: Castorice / Evernight / Trailblazer (Remembrance) / Hyacine

A very accessible version of the premium team, replacing Cyrene with Trailblazer (Remembrance). RMC gives Castorice extra HP drain targets via Mem’s actions, provides a 36% True DMG bonus to both Castorice and Netherwing when Mem’s support is active on them, and contributes 10% CRIT Rate plus substantial CRIT DMG to the party. Since Trailblazer (Remembrance) is free, this is one of the best-value teams on the roster.

F2P Friendly Team: Castorice / Trailblazer (Remembrance) / Tribbie / Hyacine

An excellent free-to-play option that clears all endgame content comfortably. Tribbie provides RES PEN and a 30% DMG Taken debuff on enemies — rare multipliers that Castorice values highly because she is already saturated on common buffs like DMG% and CRIT DMG. Tribbie also scales off the team’s high HP pool, giving her respectable personal damage output. This team is recommended for most players before chasing Evernight or Cyrene.

Dual-Carry HP Synergy: Castorice / Mydei / Tribbie / Hyacine

A creative dual-carry setup built on mutual HP drain. Mydei is a Destruction DPS who also scales off HP and actively loses HP as part of his own mechanics. His HP consumption generates Newbud for Castorice. Castorice’s drain in turn accelerates Mydei’s kit. Both characters benefit from Tribbie’s stat-agnostic amplification, and Hyacine keeps everyone alive through the constant dual-drain pressure. This team is especially strong in content with multiple tough enemies and is one of the most enjoyable compositions to play.

Budget Accessible Team: Castorice / Trailblazer (Remembrance) / Ruan Mei / Gallagher

The most accessible team that still performs respectably in endgame. Ruan Mei gives a passive DMG% buff, SPD bonus, and Break efficiency that helps cycle faster. Gallagher provides reliable direct healing with good SP efficiency. This is the team to run if you haven’t pulled newer premium supports yet.

Castorice Trace Priority

Follow this order when allocating upgrade materials:

• Major Traces first — A2 and A4 are mandatory. A2 (Contained Dark Tide) converts ally healing into Newbud, which is the core mechanic that makes fast rotation cycles possible. A4 (Inverted Torch) grants Castorice and Netherwing 40% SPD when HP is above 50%, dramatically improving action economy. Unlock both of these before touching anything else.
• Skill – Second. Higher Skill level increases HP drain multipliers and joint attack DMG. More drain means faster Newbud generation and bigger numbers on Netherwing’s joint strikes.
• Ultimate – Third. Higher Ultimate level boosts Netherwing’s damage multipliers and strengthens the All-Type RES reduction on the Lost Netherland Territory.
• Talent – Fourth. The Talent’s stacking 20% DMG bonus from ally HP loss scales with level. Increases damage output passively across the whole rotation.
• Basic Attack – Last. Used occasionally for Toughness bar breaking. Contributes a small share of overall damage. Level this only after everything else is maxed.

Castorice Eidolons – Which Ones Are Worth It?

Castorice is strong at E0, but her Eidolons offer meaningful upgrades at specific thresholds.

E1 – Smooth Gameplay Upgrade

E1 allows Castorice’s Ultimate to immediately grant Netherwing 100% action advance and restores 30% Ultimate charge on Enhanced Skill use. Netherwing gains 2 extra Breath attacks per summon, resetting on the next summon. The result is smoother rotations and more Netherwing damage per cycle. For Castorice-focused players, E1 plus signature Light Cone is often rated equal to or slightly above E0 plus signature in terms of overall investment return.

E2 – Best Value Eidolon (Recommended Stop Point)

E2 is where Castorice’s power truly takes off. It grants 30% faster access to Netherwing per rotation — meaning she summons the dragon significantly more frequently. It also adds 2 extra Breath attacks per summon and delivers a 50%+ total damage boost when fully calculated. Community estimates place E2’s DPS gain as multiple times larger than E1’s gain. If you are investing seriously in Castorice, E2 is the clear target. Beyond E2, the cost-to-benefit ratio drops sharply for most players.

E4 – Sustain Quality-of-Life

E4 increases the HP all allies receive when healed, which indirectly boosts Newbud generation since more restored HP means more available HP to drain on the next cycle. It is a decent survivability Eidolon but not worth chasing over E2 investments.

E6 – High-Investment Endgame Spike

E6 significantly boosts overall damage and adds a Toughness reduction mechanic that ignores Weakness types, triggering the Quantum Weakness Break effect on any enemy. The raw power jump is impressive. Practically, E6 is for dedicated Castorice mains with extraordinary resource reserves. The cost to reach it is extremely high relative to what most players can reasonably target.

Castorice Rotation Guide – How to Play Her

Castorice’s rotation has a clear rhythm. Once you feel it, the fights flow naturally.

Starting the Fight

Always use her Technique before entering a battle. Netherwing spawns at 50% HP with immediate 100% action advance, and Castorice starts with 30% Newbud already loaded. Keep in mind that this opening Netherwing cannot be buffed by Trailblazer (Remembrance) or action-advance supports on its very first turn, so cycle through it quickly and let it expire to start the properly-buffed second rotation.

Building Newbud (Pre-Ultimate Phase)

Use Castorice’s Skill each turn to drain allies’ HP and accumulate Newbud. Your healer should top teammates back up after each drain — healing also feeds extra Newbud through the A2 Trace, so this is doubly valuable. Coordinate healing just before Castorice’s turn for the best Newbud conversion per action. With a strong healer, you can fill Newbud in roughly 2–3 Skill uses before the first natural Ultimate fires.

Summoning and Sustaining Netherwing

When Newbud is full, press Ultimate. Netherwing spawns and acts immediately. While Netherwing is active, HP lost by allies now restores Netherwing’s HP instead of generating Newbud — so keep the drain and healing cycle going to sustain the dragon across all 3 of its action turns. Use the Enhanced Joint Skill to hit all enemies with AoE Quantum DMG and drain 40% of current HP simultaneously, converting it all to Netherwing HP. The longer Netherwing stays alive, the more total damage it outputs.

Returning to Newbud Phase

After Netherwing despawns, resume Skill usage to refill Newbud for the next cycle. Most fights end within one to two complete Netherwing cycles with good relic investment and a strong team.

Should You Pull Castorice in HSR 4.3?

Yes — Castorice is one of the safest and most rewarding long-term investments in Honkai Star Rail right now. She is T0 across all three endgame modes in patch 4.3. Very few DPS characters in the game’s history have held that position across MoC, PF, and AS simultaneously for this long after launch.

Her practical advantages are significant. She is completely SP neutral — teammates always have Skill Points to spend. Her global revival passive adds a free safety net in hard content. She has no inherent Weakness restrictions since her Ultimate forces All-Type RES reduction. And she works in multiple team archetypes: dedicated Remembrance teams, dual-carry HP synergy teams, and even mixed comps with characters like Mydei or Blade.

The two honest caveats: her signature Light Cone gap is large, so if you pull her without it, plan to grab it on a rerun. And she absolutely cannot run shielders — plan your sustain character accordingly. Neither limitation is steep, but both require awareness.

Want to compare your options before pulling? Check our guides for Phainon, Acheron, and The Herta for alternative DPS options. For supports and healers to pair with Castorice, see our guides for Evernight, Tribbie, Cyrene, Hyacine, and Luocha.

Castorice 4.3 Build Guide – Quick Summary

• Role: Main DPS / Hypercarry
• Element: Quantum
• Path: Remembrance
• Best Light Cone: Make Farewells More Beautiful (signature) > Sweat Now, Cry Less (Battle Pass) > Time Waits for No One
• Best 4-Piece Relic Set: Poet of Mourning Collapse
• Best Planar Ornament: Bone Collection’s Serene Demesne
• Body Main Stat: CRIT Rate
• Feet Main Stat: SPD
• Sphere Main Stat: HP% (below 8,500 HP) / Quantum DMG Bonus (above 8,500 HP)
• Rope Main Stat: HP%
• Stat Goals: 7,000+ HP out-of-battle, ~100% CRIT Rate in-combat, 200%+ CRIT DMG, 134+ SPD
• Trace Priority: Major Traces (A2 & A4) > Skill > Ultimate > Talent > Basic Attack
• Best Eidolon: E2 (30% faster Netherwing cycles + 50%+ total damage boost)
• Best Teams: Castorice / Evernight / Cyrene / Hyacine (premium) — Castorice / TB Remembrance / Tribbie / Hyacine (F2P)
• Critical Rule: Never use shielders. Always use direct healers.
• Endgame Tier: T0 in MoC, PF, and AS as of patch 4.3

For full skill calculations, complete Eidolon breakdowns, and the latest meta placement data, visit the complete Castorice guide on GamingProMax.

For official version notes and event details, check the HoYoverse official Honkai Star Rail news page.