Cerydra is the latest Harmony Path character in Honkai: Star Rail, and she brings a very unique kit built around her Military Merit and Charge system.
While her design leans toward niche hypercarry support, she offers one of the most interesting mechanics yet: duplicating skills with her Coup de Main ability.
This guide will cover everything you need to know about Cerydra, including her kit breakdown, eidolons, best builds, relic recommendations, light cone options, and ideal team comps.
Cerydra’s Kit Breakdown
Cerydra is a Wind Harmony unit who specializes in empowering a hypercarry ally. Here’s how her abilities work:
Skill: Military Merit
Grants a permanent ATK buff to one ally based on Cerydra’s ATK. At level 10, this buff is 24% of her ATK (e.g., ~960 ATK if she has 4000). Every time the buffed ally attacks, Cerydra also deals additional damage (up to 20 times, refreshed on her Ultimate).
Charge System & Peerage
Cerydra builds up to 8 Charges. At 6 Charges, the Military Merit buff is upgraded to Peerage, which adds:
- +72% CRIT DMG (skill damage only)
- +10% All-Type RES PEN
- Skill duplication via Coup de Main (copies an ally’s skill and casts it again).
After triggering Coup de Main, the buff reverts to Military Merit and 6 Charges are consumed.
Ultimate
AoE attack that grants 2 Charges and can be used off-turn, allowing you to force Peerage activations at key moments.
Talent
The ally with Military Merit gives Cerydra additional Charges whenever they use a Basic ATK or Skill.
Technique
Grants Military Merit to the active ally before battle and automatically uses her Skill once when combat begins—great for buff uptime and an instant Charge.
Ascension Passives
- A2: +CRIT DMG for every 100 ATK above 2000 (caps at 360%).
- A4: Grants Cerydra 100% CRIT Rate on all attacks.
- A6: +20 SPD to herself and her Merit ally for 3 turns, plus 5 Energy whenever the Merit ally uses a Basic/Skill.
Eidolons Overview
- E1: DEF Ignore buff for the Merit ally (+16% normally, +36% if Peerage is active). Also restores 2 Energy when using Skill. Extremely strong synergy with Phainon since it accelerates Coreflame gain.
- E2: +40% DMG buff to the Merit ally, while increasing Cerydra’s damage by 160%. More useful for allies than herself.
- E4: Increases Ultimate DMG. Not a huge priority.
- E6: Grants the Merit ally +20% RES PEN permanently. Also boosts Cerydra’s Additional DMG multiplier by 300%, finally giving her some self-damage presence.
Verdict: E1 is game-changing with Phainon but less impactful with other DPS. E6 turns her into a more relevant hybrid support-damage unit.
Best Builds for Cerydra
Relics
- Sacerdos Set: Best for Phainon teams since buffs can be snapshotted.
- Eagle Set: Extra turns = more Ultimates = more Coup de Mains.
- 2-Piece Mix (ATK% + SPD): Solid general option, especially outside Phainon comps.
Planar Ornaments
- Lushaka – Excellent for teamwide DMG buffs + Energy Regen.
- Penacony – Works well if paired with Anaxa.
- Other buffing planars are acceptable, depending on team comp.
Main Stats
- Chest: ATK% (or HP% if sustainless team)
- Boots: SPD (ATK for Phainon one-turn setups)
- Orb: ATK%
- Rope: Energy Regen (ATK if rotations are short)
Stat Goals
- SPD: 140+ (or adjusted for rotation breakpoints with advancers).
- ATK: 4000+ in combat.
- Stack HP/DEF from substats for survivability. CRIT DMG is less valuable since she self-buffs heavily.
Best Light Cones
Epoch Etched in Golden Blood (Signature):
- High base ATK for buff scaling.
- +64% ATK, +54% Skill DMG buff, and bonus SP from Ult.
- Best-in-slot but niche—only great for Cerydra.
The Forever Victual:
- Up to +80% ATK from stacking.
- Strong stat stick and widely available.
Flowing Nightglow (Robin’s Cone):
- Excellent alternative—grants ATK, buffs, and Energy.
Best Teams for Cerydra
Cerydra is not a universal Harmony buffer like Bronya or Robin. Instead, she shines with specific DPS who rely heavily on Skill-based damage:
Phainon (Best Partner):
- Cerydra accelerates Coreflame gain, duplicates Phainon’s 4-Scourge Skill, and boosts SPD so he can run ATK boots.
- E1 synergy is incredibly strong, making her almost tailored for Phainon.
Anaxa:
- His natural Skill duplication interacts beautifully with Coup de Main, stacking multiple skills for insane burst multipliers and Pure Fiction clears.
Archer:
- Works in sustainless comps where SP management is critical. Archer’s skill spam feeds her Charges quickly, and she keeps SP positive.
Other DPS (less optimal):
- The Herta (E1+): Can double-enhance Skills, though interpretation stacks still limit her.
- Seele: Extra turns from Resurgence = more Coup de Mains, but her damage is ult-heavy, making the synergy clunky.
Cerydra is mostly a “Phainon specialist,” with Anaxa as her secondary synergy. Other DPS options are playable but not worth pulling for.
Should You Pull for Cerydra?
Cerydra introduces one of the most creative mechanics in Honkai: Star Rail with her skill duplication system. While she’s not a universal buffer, her value skyrockets in Phainon comps, where she feels practically tailor-made. Anaxa players can also get a lot of mileage out of her, while Archer sustainless builds may find her useful for SP stability. If you don’t own Phainon or Anaxa, Cerydra is a safe skip in favor of more versatile Harmony units. But if you’re a Phainon main? She’s a game-changer and easily worth pulling.