Castorice functions as a cornerstone for the Quantum Remembrance archetype, introducing a sophisticated summon-based playstyle centered around her dragon companion, Netherwing. Unlike traditional damage dealers who rely on high Attack stats, the Castorice HSR kit scales primarily with Max HP, making her one of the tankiest yet most lethal DPS units in the current meta. Understanding the delicate balance between team HP consumption and Netherwing’s offensive output is essential for any player looking to maximize her potential in high-level endgame content like Memory of Chaos and the newly updated Remembrance-themed challenges.

Core Mechanics of the Castorice HSR Kit

The fundamental logic of the Castorice HSR kit revolves around a symbiotic relationship between the character, her team, and the summoned entity, Netherwing. As a Remembrance unit, she does not act alone; instead, her Ultimate serves as the gateway to her primary damage source.

Netherwing Summon and the New Bud Resource

Instead of conventional Energy, Castorice utilizes a unique resource called "New Bud." This resource is accumulated through team activity, specifically whenever allies lose HP or receive healing. Her Ascension 2 passive is critical here, converting incoming healing into New Bud points.

Once the New Bud gauge is filled, Castorice can deploy her Ultimate to summon Netherwing and initiate the "Lost Netherland" domain. Within this domain, enemies suffer a 20% All-Type Res reduction, which significantly boosts the team's total damage floor. Netherwing operates with a fixed Speed of 165, ensuring it takes frequent turns regardless of Castorice’s own speed investments. However, managing Netherwing’s HP is the player's primary concern. The summon consumes its own health to perform its most powerful attack, Scorch Breath. If Netherwing's health drops below a specific threshold (25%), it triggers a massive multi-hit bounce attack before departing, which heals the entire team upon its exit.

Skill Synergy: Sacrifice for Power

Her Skill acts as the primary manual trigger for Netherwing’s mechanics. In her base state, the Skill consumes 30% of all allies' current HP to deal Blast damage and rapidly charge the New Bud resource. Once Netherwing is on the field, the Skill evolves into a joint attack. It still consumes ally HP, but instead of dealing direct damage from Castorice herself, it redirects that life force to heal Netherwing. This creates a loop: the team sacrifices HP to keep the dragon alive, allowing it to stay on the field longer and stack more Scorch Breath applications.

Essential Materials for Leveling and Traces

Building Castorice to her maximum level requires a significant investment in specific 3.x version materials. To reach Level 80 and maximize her Traces, players should prioritize gathering the following resources:

  • Character Ascension: You will need roughly 65x Darkveil Moonlight, which is dropped by the newer Stagnant Shadow bosses found in the Chrysos regions. Common drops like Ethereal Omen, Echoing Wail, and Eternal Lament are also required in large quantities (15, 15, and 15 respectively for the final stages).
  • Trace Development: The Bīja of Consciousness series is the core material for her skills. This involves farming the Calyx (Crimson) for Seedling of Manas, Flower of Ālaya, and the final Bīja. For the ultimate Trace levels, players must obtain 12x Auspice Sliver from the weekly Echo of War boss.

Prioritizing her Trace levels is straightforward: focus entirely on her Skill and Talent first. Since her Basic Attack contributes negligible damage and she rarely uses it in an optimal rotation, it can be left at Level 1 to conserve resources. Her Ultimate level is also important as it scales the Res reduction within the Lost Netherland domain.

Relic Optimization: Breaking the Speed Barrier

The most common mistake when building the Castorice HSR kit is over-investing in Speed. Because of her unique passive and her preferred Relic set, standard DPS gearing rules do not apply.

The Poet of Mourning Collapse Advantage

The 4-piece Poet of Mourning Collapse is the undisputed best-in-slot for Castorice. This set provides a massive 32% Crit Rate and 10% Damage bonus, but only if the wearer's Speed remains below 135. Under normal circumstances, this would make a character too slow for the current meta. However, Castorice features a built-in "cheat": when her HP is above 50%, she gains a flat +40% Speed buff that does not count toward the Relic set's restrictive threshold. This allows her to benefit from the set's full offensive bonuses while still moving at a high frequency in combat.

Planar Ornaments and Main Stat Priorities

For Planar Ornaments, Bone Collection’s Serene Demesne is the premier choice. It scales directly with Max HP and provides Crit Damage bonuses that apply to both Castorice and Netherwing.

  • Body: Crit Damage (The Poet set provides enough Crit Rate to hit the 100% cap easily with sub-stats).
  • Feet: HP% (Speed boots are unnecessary and often detrimental to the Poet set bonus).
  • Sphere: HP% or Quantum Damage. While Quantum Damage provides a slightly higher ceiling in solo-damage scenarios, HP% offers more consistency and increases Netherwing's survivability.
  • Link Rope: HP%. Energy Regeneration Rate is less valuable because New Bud accumulation is tied to HP fluctuations rather than traditional energy mechanics.

Sub-stat priority should follow a strict hierarchy: Crit Damage > HP% > Crit Rate (until 100% in-combat) > Flat HP. Speed should be avoided entirely to ensure the 135 threshold is never breached.

Light Cone Selection: Signature vs. Alternatives

Castorice is notably restrictive regarding Light Cone options. Her kit’s reliance on Max HP and summon-specific mechanics means that many traditional Destruction or Erudition cones (depending on the path shift) do not provide adequate value.

  1. Netherwing’s Oath (Signature): This is her best-in-slot by a significant margin. It offers the highest base HP in the game and provides a 30% Defense Ignore effect that applies to Netherwing’s attacks. Furthermore, it grants an Action Advance when Netherwing leaves the field, fixing any potential rotation delays.
  2. Sweat Now, Cry Less (4-Star Battle Pass): If the signature cone is out of reach, this is the most viable secondary option. It provides a decent HP boost and improves the wearer's survivability, though the damage output is approximately 20-25% lower than the signature.
  3. To Evernight’s Stars: A strong alternative for those who have pulled for other Remembrance units. It provides general damage buffs that benefit summoner playstyles.

Free-to-play players may find her difficult to gear, as standard 3-star or generic 4-star cones often focus on Attack, which offers very little scaling for Castorice's HP-centric kit.

Top-Tier Team Compositions

To unlock the full potential of the Castorice HSR kit, you must surround her with characters capable of manipulating HP or providing high-frequency healing. She thrives in the "Chrysos Heirs" archetype.

The Premium Hypercarry Team

  • Main DPS: Castorice
  • Support 1: Evernight (Provides massive debuffs and Quantum shred).
  • Support 2: Cyrene (Offers Turn Advance and Crit buffs specifically for summons).
  • Sustain: Hyacine (The essential healer for this team. Hyacine can consume her own HP and increase the team's Max HP, which accelerates Castorice’s New Bud generation significantly).

The HP-Drain Synergy Team

Castorice also works exceptionally well in a double-DPS setup with older units who possess self-damage mechanics.

  • Main DPS: Castorice
  • Sub-DPS: Blade or Jingliu. Every time Blade consumes his own HP or Jingliu drains health from the team, Castorice gains New Bud points. This synergy allows Netherwing to be summoned much more frequently than in a standard hypercarry setup.
  • Support: Remembrance Trailblazer (E1+). This unit provides specific buffs to the Remembrance path and enhances the "True Damage" dealt by summons.
  • Sustain: Gallagher or Lingsha. Both provide consistent healing-over-time which keeps the HP-drain loop sustainable without the risk of a total party wipe.

F2P-Friendly Team

For players with a limited roster, Castorice can be paired with Lynx. Lynx’s Skill increases a target’s Max HP, which is a direct damage buff for Castorice. Combining them with Pela for Defense reduction and the Remembrance Trailblazer for path synergy creates a competent team capable of clearing most mid-to-high level content.

Advanced Combat Tactics

Mastering Castorice requires more than just clicking buttons. You must monitor the "Lost Netherland" domain duration and Netherwing's current HP percentage.

One advanced tactic involves timing Castorice’s Skill usage right before Netherwing takes its turn. If Netherwing is at roughly 30% HP, using the Skill to heal it back up can allow for one more Scorch Breath attack before it drops into its final "explosion" phase. This effectively extends the summon's field time and increases the total damage per Ultimate cycle.

Additionally, her global passive—the delay death effect—should be treated as a strategic resource. In high-difficulty content, you can afford to play more aggressively with HP consumption, knowing that Castorice provides a one-time safety net for any ally who takes a lethal hit, provided your healer (like Hyacine or Lynx) has an Ultimate ready to immediately restore them.

Final Verdict for the 2026 Meta

As of April 2026, Castorice remains a top-tier investment for players who enjoy tactical, summon-oriented gameplay. While her gearing requirements are strict—requiring specific HP-scaling relics and a strong preference for her signature Light Cone—the resulting damage output is unrivaled in multi-target scenarios. She effectively bridges the gap between the Quantum and Remembrance paths, offering a unique playstyle that rewards careful HP management and team-building synergy. If you are looking for a unit that scales into the late-game and offers a fresh mechanic compared to traditional ATK-based carries, the Castorice HSR kit is a premiere choice for your roster.