Castorice has arrived in Honkai: Star Rail as a paradigm-shifting Quantum DPS following the Path of Remembrance. Unlike traditional damage dealers who thirst for Attack and Speed, Castorice thrives on high HP pools and the strategic sacrifice of her teammates' health. As the first major HP-scaling summoner in the 3.x era, building her correctly requires a fundamental shift in how you evaluate relics and team synergies.

To maximize her potential, you must focus on her memosprite, Netherwing, which acts as her primary source of Area of Effect (AoE) devastation. The goal is to reach a critical mass of HP—ideally above 7,000—while balancing Crit stats to ensure Netherwing's "Breath Scorches the Shadow" hits like a falling star.

Understanding the Core Mechanics of Castorice

Before diving into the gear, it is essential to understand why certain stats are prioritized. Castorice’s kit revolves around "Newbud" points and the "Netherwing" summon.

The Newbud and Ultimate Cycle

Castorice does not use traditional Energy in the same way most characters do. Instead, she accumulates "Newbud" points. For every 1 point of HP lost by any ally on the field (including herself), she gains 1 Newbud point. Once the Newbud meter reaches its limit, she can activate her Ultimate, "Doom Shriek, Dawn’s Chime."

This mechanic means her "Energy" generation is entirely tied to how frequently her team loses HP. This is why characters who consume their own HP, or enemies who deal frequent AoE damage, actually accelerate her rotation.

Netherwing: The True Damage Dealer

When the Ultimate is cast, Netherwing enters the battlefield. This memosprite inherits a massive portion of Castorice's HP and Crit stats. Crucially, Netherwing has a fixed base Speed of 165. Because Netherwing's actions are advanced by 100% upon summoning, and it possesses such high base speed, Castorice herself does not need to invest heavily in Speed. In fact, many of her best gear sets actively punish her for being too fast.

The Global Passive: Mooncocoon

One of the most overlooked aspects of Castorice is her global passive. She can provide a "Mooncocoon" state to allies, preventing them from being knocked out and effectively bearing the damage through Netherwing. This utility makes her a hybrid of a powerhouse DPS and a safety net for the team, provided Netherwing is active.

Best Relic Sets for Castorice

Choosing the right relic set for Castorice is a matter of maximizing her "low-speed, high-HP" profile.

The BiS: Poet of Mourning Collapse (4-Piece)

The "Poet of Mourning Collapse" is undeniably the best-in-slot (BiS) relic set for Castorice.

  • 2-Piece Bonus: Increases Quantum DMG.
  • 4-Piece Bonus: Provides a massive boost to Crit Rate for both the wearer and their summoned memosprite, but this bonus is only fully active if the wearer’s Speed remains below a certain threshold (typically 110 or lower).

In our testing, the Poet set outperforms the "Genius of Brilliant Stars" in almost every scenario because it addresses the Crit Rate requirements for both Castorice and Netherwing simultaneously. Since Netherwing accounts for roughly 70-80% of your total team damage, a set that buffs the summon specifically is invaluable.

The Alternative: Longevous Disciple (4-Piece)

If you are still farming for the Poet set, "Longevous Disciple" is a respectable placeholder. Since Castorice's skill consumes ally HP and she often takes damage, the 12% Crit Rate stack is easy to maintain. However, it lacks the specific memosprite synergy found in the newer sets.

The Quantum Specialist: Genius of Brilliant Stars (4-Piece)

Against enemies with Quantum Weakness, the 20% Defense Ignore from the Genius set remains competitive. However, because Castorice’s signature Light Cone and certain teammates (like Pela) already provide significant Defense Shred, you may run into diminishing returns compared to the raw Crit and HP stats provided by newer options.

Best Planar Ornaments

Your choice of Planar Ornaments should focus on the interaction between HP and Crit DMG.

Bone Collection’s Serene Demesne

This is the definitive choice for Castorice. It increases the wearer’s Max HP and, more importantly, provides a significant Crit DMG boost when the wearer’s Max HP exceeds a specific limit (which Castorice hits easily). This set was tailor-made for the Remembrance path’s HP-scaling focus.

The Wondrous Banana Musement Park

If you are focusing entirely on Netherwing's burst damage, the Banana Musement Park set offers a high Crit DMG bonus specifically for summons. While it doesn't provide the HP sustain of Bone Collection, the damage ceiling in short fights (like Memory of Chaos) can be slightly higher if your substats are perfect.

Main Stat and Substat Priorities

Precision in stat distribution is what separates a mediocre Castorice from a top-tier one.

Body: Crit DMG or Crit Rate

Because the "Poet of Mourning Collapse" set and her trace nodes provide a significant amount of Crit Rate, most players should aim for a Crit DMG body. Your goal is to reach a 1:2 ratio, aiming for roughly 80% Crit Rate and 160%+ Crit DMG during combat.

Feet: HP%

Do not use Speed boots. This is the most common mistake. Castorice benefits from staying slow to maintain the Poet set’s bonuses and to allow her allies to take more turns, thereby losing more HP and fueling her Newbud meter faster. HP% boots significantly increase her base damage and survivability.

Planar Sphere: HP% (Often better than Quantum DMG%)

In most damage dealers, an Elemental DMG sphere is mandatory. However, Castorice gains an enormous amount of DMG% bonuses from her Talent ("Desolation Across Palms") and her Ultimate's "Lost Netherland" territory. Because her base HP is so high, an HP% Sphere often results in higher total damage output while making her nearly unkillable.

Link Rope: HP% or Energy Regeneration Rate

In a dedicated Remembrance team with high HP-consumption (like with Hyacine), an HP% Rope is preferred for the raw scaling. However, if you find your Ultimate rotation feels sluggish (taking more than 3 turns to summon Netherwing), an Energy Regeneration Rate rope can smooth out the gameplay, though it technically lowers your damage ceiling per hit.

Substat Priority

  1. HP%: Every roll is valuable.
  2. Crit Rate / Crit DMG: Maintain the balance.
  3. Flat HP: More useful on her than on almost any other character.
  4. Effect Resistance: To ensure she doesn't get CC'd, which would prevent her from using her Skill to generate Newbud.

Best Light Cones for Castorice

The gap between her signature weapon and F2P options is noticeable but manageable with the right team.

1. Make Farewells More Beautiful (Signature 5-Star)

This Light Cone is a monster. It provides a massive HP% boost and allows the wearer and Netherwing to ignore a portion of the enemy's defense whenever HP is consumed. It also features a unique action-advance mechanic that kicks in after Netherwing disappears, allowing Castorice to quickly restart her Newbud gathering phase.

2. To Evernight’s Stars (Alternative 5-Star)

A strong second choice that focuses more on the "Remembrance" path's utility. It provides high base stats and boosts the damage of summons based on the wearer’s Max HP.

3. The Flower Remembers (4-Star Battle Pass)

For low-spenders, this is the best 4-star option. It offers a consistent HP bonus and increases Crit DMG. It is remarkably stable and scales well with Refinements.

4. Flames Afar (F2P / Forgotten Hall Shop)

If you are strictly Free-to-Play, "Flames Afar" is a functional choice. While it was originally designed for Destruction characters like Blade, the HP-scaling and the DMG boost upon losing HP synergize well enough with Castorice’s fundamental loop to be viable.

Trace Priority and Leveling

Investing resources efficiently is key to her growth.

  1. Talent (Desolation Across Palms): This is your priority. It governs the DMG% increase for both Castorice and Netherwing based on HP lost.
  2. Ultimate (Doom Shriek, Dawn’s Chime): Directly impacts the RES PEN and summoning power of Netherwing.
  3. Skill (Silence, Wraithfly’s Caress): Determines how much HP you consume and the initial damage of her "Boneclaw" enhanced skill.
  4. Basic Attack: Can be left at level 1; you should almost never be using it.

Major Traces to Unlock Immediately:

  • Contained Dark Tide: Converts healing received into Newbud or Netherwing HP. This is vital for synergy with healers like Hyacine or Luocha.
  • Inverted Torch: Provides a 40% Speed boost when her HP is high, helping her act just enough without ruining her relic bonuses, and boosts Netherwing's Speed upon killing enemies.

Best Team Compositions for Castorice

Castorice requires a specific team architecture: she needs units that can either survive her HP drain or benefit from it.

The Premium "Remembrance" Team

  • Main DPS: Castorice
  • Support 1: Evernight (Provides massive offensive buffs and scales with the Remembrance path).
  • Support 2: Cyrene (Offers consistent damage amplification and HP management).
  • Sustain: Hyacine (The perfect partner. Hyacine increases the team’s Max HP and accelerates Newbud charging by consuming HP through her "Little Ica" mechanic).

This team focuses on maximizing the "Newbud" generation. Hyacine’s ability to increase the team's Max HP directly increases Castorice’s damage ceiling, making it the highest-performing comp in the game for her.

The F2P-Friendly Team

  • Main DPS: Castorice
  • Support 1: Remembrance Trailblazer (Ice) (Provides turn-advance, true damage, and Crit buffs. Extremely effective for an E0 Castorice).
  • Support 2: Pela (Universal Defense shredder that helps Netherwing ignore even more of the enemy's armor).
  • Sustain: Lynx (Increases Castorice’s Max HP with her Skill and provides necessary cleansing).

The Dual-DPS "HP Sacrifice" Comp

  • Main DPS: Castorice
  • Sub-DPS: Blade or My Dei
  • Support: Sunday or Sparkle
  • Sustain: Gallagher or Luocha

In this setup, Blade or My Dei act as secondary damage dealers who consume their own HP. Every time Blade loses HP to perform an attack, he feeds Newbud points to Castorice. This creates a high-pressure offensive environment where both units are constantly fueling each other's mechanics.

Strategic Tips for Playing Castorice

To truly master Castorice, you need to think a few turns ahead.

Managing the HP Drain

Castorice’s skill drains 30% of your allies' current HP. If you use it recklessly when your team is already low, you risk hitting the 1 HP cap. While "Mooncocoon" can prevent death, you lose the offensive momentum if Netherwing has to spend its time "bearing damage" instead of attacking. Always ensure your sustain unit (Hyacine/Lynx) has an Ultimate ready before a major drain phase.

Timing the Summon

Wait for your supports to apply their debuffs (like Pela’s Ult or Evernight’s buffs) before you cast Castorice’s Ultimate. Netherwing inherits the stats Castorice has at the moment of summoning. If you buff Castorice while Netherwing is already on the field, the memosprite will benefit, but capturing the "Snapshot" of a fully buffed Castorice is the most efficient way to play.

The "Slow" Advantage

Because Castorice is slow, she doesn't consume buffs as quickly as a fast Seele or Jingliu would. This allows buffs from characters like Sunday or Bronya to linger on her for longer, potentially covering multiple Netherwing actions within a single buff window.

Conclusion

Building Castorice is a journey into the high-risk, high-reward heart of the Remembrance path. By focusing on a massive HP pool, utilizing the "Poet of Mourning Collapse" set, and pairing her with HP-manipulating supports like Hyacine or the Remembrance Trailblazer, you can unlock a level of AoE damage that few other characters can match. Remember: for Castorice, every drop of health lost is a step toward total battlefield domination.

FAQ

Is Castorice good for Pure Fiction? Yes, she is exceptional. Because Netherwing deals heavy AoE damage and has a very high base Speed, she can clear waves of enemies effectively, even if the main body (Castorice) is slow.

Should I pull for her Eidolons or her Light Cone first? Her Light Cone ("Make Farewells More Beautiful") is generally a higher priority than her E1. The Defense Ignore and HP scaling it provides are difficult to replace with 4-star options. However, her E2 is a massive quality-of-life upgrade for her rotation.

Can I run her without a healer? Only in very specific "nuke" setups or if you are using a high-Eidolon Aventurine/Fu Xuan, but it is not recommended. Her HP drain is aggressive, and without a way to replenish that health, your "Newbud" generation will stall once everyone hits 1 HP.

What is the minimum HP I should aim for? For endgame content like Memory of Chaos 12, aim for at least 7,000 HP. Top-tier builds often exceed 8,500 HP with the right Planar Ornaments and signature Light Cone.