Castorice functions as a pivotal Quantum unit following the Path of Remembrance in Honkai: Star Rail. Unlike traditional damage dealers that rely solely on Attack or Critical stats, her kit introduces complex HP-scaling and the "Memo Sprite" mechanic, specifically through her summon, Netherwing. Maximizing her potential requires a significant investment in specialized materials found within the newer regions of the star rail, particularly those introduced in the Amphoreus arc. This analysis provides a breakdown of every material needed to ascend Castorice to level 80 and max out her trace tree, ensuring resource efficiency for high-end gameplay.

Castorice Ascension Materials: Level 1 to 80

Ascending Castorice to Level 80 is the primary objective to unlock her base HP potential, which directly correlates to her damage output and the survivability of her summoned entities. The progression follows the standard six-phase ascension structure, requiring a mix of monster drops and stagnant shadow rewards.

Total Ascension Cost

To reach Level 80, the following resources are required:

  • Ethereal Omen x15
  • Echoing Wail x15
  • Eternal Lament x15
  • Darkveil Moonlight x65
  • Traveler's Guide x290 (approximate)
  • Credits x888,000

Ascension Phase Breakdown

  • Level 20 to 30: Requires Ethereal Omen x5 and 22,000 Credits.
  • Level 30 to 40: Requires Ethereal Omen x10 and 33,000 Credits.
  • Level 40 to 50: Requires Darkveil Moonlight x3, Echoing Wail x6, and 56,000 Credits.
  • Level 50 to 60: Requires Darkveil Moonlight x7, Echoing Wail x9, and 124,000 Credits.
  • Level 60 to 70: Requires Darkveil Moonlight x20, Eternal Lament x6, and 214,000 Credits.
  • Level 70 to 80: Requires Darkveil Moonlight x35, Eternal Lament x9, and 438,000 Credits.

Darkveil Moonlight is obtained from the Stagnant Shadow: Shape of Gelid Moon located in the Murmuring Woods. Given that Castorice shares this material with other recent Quantum characters like Tribbie, players should manage their Trailblaze Power carefully. The Ethereal Omen series is dropped by Black Tide creatures, which are prevalent in the Grove of Epiphany and other areas within Amphoreus. These enemies are unique to the 2025-2026 content cycle, so legacy players returning to the game will need to unlock these new maps before farming.

Comprehensive Trace Materials for Castorice

Tracing Castorice is where the bulk of the resource investment lies. Her role as a rotation accelerator and HP-based DPS means that her Skill, Ultimate, and Talent all hold equal weight in combat performance. Neglecting even one branch can result in a significant drop in her territory effectiveness ("Lost Netherland").

Total Trace Requirements (Levels 1-10)

For those aiming to max out all traces, including basic attacks and the secondary ability tree, the total count is as follows:

  • Bija of Consciousness x18
  • Seedling of Manas x69
  • Flower of Alaya x139
  • Ethereal Omen x41
  • Echoing Wail x56
  • Eternal Lament x58
  • Auspice Sliver x12
  • Tracks of Destiny x8
  • Credits x3,000,000

The Bija of Consciousness Series

The Bija of Consciousness, Seedling of Manas, and Flower of Alaya are the Path of Remembrance's specific trace materials. These are farmed via the Calyx (Crimson): Bud of Remembrance found in the Strife Ruins. Since Castorice's damage scaling is tied to the collective HP levels of the team and the accumulation of "New Bud" stacks, leveling these traces increases the conversion ratio of HP lost to damage dealt.

Weekly Boss Drops: Auspice Sliver

The Auspice Sliver is a rare material dropped by the Echo of War boss: Shadow of Feixiao and Ecliptic Inner Beast. This boss is found on the Sky Splitter in the Xianzhou Luofu. Despite her origin in Amphoreus, Castorice relies on this Xianzhou-based material for her high-level trace nodes (Levels 8, 9, and 10) and for unlocking her major Bonus Abilities. As there is a limit of three Echo of War rewards per week, prioritizing Castorice over other characters like Aglaea may be necessary if you are building them simultaneously.

Trace Upgrade Priority

Given the high cost of Flower of Alaya and Credits, following a priority list is recommended for efficient progression:

  1. Ultimate (Doom Shriek, Dawn’s Chime): This should be the first to reach Level 10. The Ultimate summons the Netherwing sprite and deploys the "Lost Netherland" territory. Upgrading this directly increases the RES reduction debuff applied to enemies, which scales the entire team's damage.
  2. Talent (The Maximum Limit of “New Bud”): This trace governs the damage boost Castorice and her sprite receive when allies lose HP. In the current high-difficulty meta, maximizing this stackable 20% DMG bonus is essential.
  3. Skill (Silence, Wraithfly’s Caress / Boneclaw, Doomdrake’s Embrace): This is her primary method of HP manipulation. While vital, its raw damage scaling is secondary to the utility provided by her Ultimate.
  4. Bonus Abilities (Ability 1: Moon Cocoon Synergy, etc.): These should be unlocked as soon as the level requirement is met, as they provide unique mechanics like death-prevention states.
  5. Basic Attack: Can be left at Level 1 or 4 unless you have excess resources, as her rotation typically avoids basic attacks in favor of Skill spam to build "New Bud" points.

Light Cone Materials: "Make Farewells More Beautiful"

To complement Castorice, her signature 5-star Light Cone, "Make Farewells More Beautiful," is the optimal choice. Upgrading this weapon from level 1 to 80 requires similar materials to her character traces but in different quantities.

  • Ethereal Omen x20
  • Echoing Wail x20
  • Eternal Lament x14
  • Bija of Consciousness x4
  • Seedling of Manas x12
  • Flower of Alaya x15
  • Credits x385,000

This Light Cone increases the wearer’s Max HP, which is the most critical stat for Castorice. If using F2P alternatives like "Sweat Now, Cry Less," the material requirements will change to generic 4-star consumption, but the focus on the Bija series remains consistent.

Optimal Farming Strategy and Locations

Efficiency in Honkai: Star Rail is defined by how players utilize their daily Trailblaze Power. For Castorice, the farming route is divided into three distinct zones.

1. The Amphoreus Cycle (Daily Farming)

The Murmuring Woods and Strife Ruins in the Amphoreus system are your primary hubs.

  • The Black Tide Route: Instead of just using the Calyx, players can perform daily "overworld" clears of the Black Tide monsters in the Murmuring Woods to save on Credits and gain the Ethereal Omen series without spending Trailblaze Power. This is highly recommended for players who are low on credits after the recent version updates.
  • Calyx Crimson (Strife Ruins): This should be the focus of your Trailblaze Power on days when the Echo of War is not a priority. The drop rate for Flower of Alaya is notoriously low, so using the Synthesizer to convert lower-tier materials is often necessary.

2. The Xianzhou Luofu (Weekly Priority)

Every Monday, players should immediately clear the Echo of War: Inner Beast’s Battlefield. Since Castorice requires 12 Auspice Slivers for max traces and bonus nodes, it will take at least four weeks of dedicated farming to gather enough for her alone, assuming no other characters are being leveled.

3. Synthesizing and Material Conversion

If you have excess materials from the 1.x or 2.x versions, remember to utilize the Omni-Synthesizer. You can convert stagnant shadow materials from older bosses into Darkveil Moonlight at a 2:1 ratio. While not perfectly efficient, it is a viable strategy for players who want to instantly Level 80 Castorice on day one without waiting for the Shape of Gelid Moon farm.

The Role of HP Scaling in Material Valuation

Understanding why these materials are necessary helps in prioritizing them. Castorice's "New Bud" mechanic functions by tracking the total HP lost by the team. Each point of HP lost translates to energy for her Ultimate. Therefore, the Level 80 ascension is not just for the base stats; it increases her Max HP ceiling, allowing her to survive the 30%-40% HP consumption required by her Skill.

Furthermore, her Memo Sprite, Netherwing, inherits 100% of the "New Bud" max value. If Castorice is under-leveled (e.g., stuck at level 70), the sprite's durability and damage potential are severely capped. In high-level content like the Simulated Universe or Memory of Chaos, a level-deficient Netherwing will be dismissed prematurely due to HP depletion, wasting the buffs provided by the "Lost Netherland" territory.

Credits and Experience Management

Totaling the costs for both character and Light Cone, you will need approximately 4.3 million Credits. This is a significant burden for many players. To mitigate this:

  • Maximize the Nameless Honor (Battle Pass) as it provides a substantial portion of the required Tracks of Destiny and Credits.
  • Participate in the limited-time events typically associated with new character releases in 2026, which often provide "Material Boxes" allowing you to choose the Bija or Ethereal Omen series.

Conclusion

Building Castorice is a marathon, not a sprint. Her unique position as a Quantum Remembrance support-DPS hybrid makes her a cornerstone of follow-up and HP-manipulation teams. By focusing on the Darkveil Moonlight from the Murmuring Woods and the Bija series from the Strife Ruins, players can ensure she reaches her maximum potential. Prioritize her Ultimate and Talent to secure her place as a top-tier debuffer and damage dealer, and do not underestimate the importance of her Level 80 ascension in a meta where HP is the most valuable resource.