Hiyuki’s damage lives and dies on how many Basic Attack – Iai casts you squeeze into one Foreclaimed Self window, and how long that window takes. Push for one more slash and you gain damage, but you also stretch the cycle past the buffs your supports left behind. At S0, three, four, and five Iai casts each produce a noticeably different loop.
Quick answer: Run the 4 Iai rotation. It takes about two seconds longer per cycle than the 3 Iai version, but it still finishes inside the 30-second buff window, so you keep the team amplification and lose no DPS over repeated loops.
Why the Iai count changes Hiyuki’s damage
Every Basic Attack – Iai costs 100 points of Frostheart, and Hiyuki caps at 300. So a three-slash window is the “free” version, a four-slash window needs you to rebuild 100 more Frostheart mid-combo, and a five-slash window needs 200 more. Frostheart comes back from Frostblight: Jade Cleave, Frostblight: Petalfall, and from Foreclaimed Self normal attacks landing on a target, which is why the longer loops are full of extra basic attacks and cancels.
The second limit is Frostharden Iai. Foreclaiming: Inward Vision grants exactly 3 points, and each Iai consumes one to apply 3 stacks of Glacio Chafe and grant a stack of Whiteout Bitterfrost. Once those three are spent, you already have the full 3 stacks needed for Heavy Attack – Bitterfrost: Foreclaimed Self. A fourth or fifth Iai adds raw Resonance Liberation damage, not extra Chafe or Bitterfrost.
The third limit is the clock. Hiyuki’s supports hand her a buff window she has to finish inside, and her own Outro Skill – Snowlight Blessing runs for 20 seconds on the next Resonator. Overrunning the window is what turns a “bigger” combo into a net loss.
3 Iai vs 4 Iai vs 5 Iai rotation comparison
| Rotation | Frostheart spent | Timing | Verdict |
|---|---|---|---|
| 3 Iai (standard) | 300 | Shortest cycle | Inefficient, wastes Frostheart generation. Skip it. |
| 3 Iai (advanced) | 300 | Drifts out of sync | Around a 10-second DPS loss by the fourth rotation. |
| 4 Iai (advanced) | 400 | ~2 seconds longer per cycle | Best overall. Fits the 30-second window with no buff loss. |
| 5 Iai (advanced) | 500 | Longest, tightest cycle | Highest damage, but needs very low ping and exact inputs. |
3 Iai rotation: the baseline loop and why it falls behind
The plain version is the one most players default to after reading her kit. Three basic attacks, a dash cancel, two Resonance Skill casts, then three Iai slashes. It works, it is easy, and it leaves value on the table because you are entering Iai Stance with Frostheart you never spend.
The full baseline loop looks like this: Intro Skill – Frostedge for 200 Dedication, Basic Attack stage 3 to cap Dedication at 300, hold Normal Attack for Heavy Attack – Frost Splinter: Present Self, Resonance Liberation for Foreclaiming: Inward Vision, two Frostblight casts, the five-stage Foreclaimed Self basic string to reach 300 Frostheart, dodge into Iai Stance, three Iai, hold Normal Attack for Heavy Attack – Bitterfrost: Foreclaimed Self, then Foreclaiming: Blade Liberation and Outro.
The advanced 3 Iai variant tightens that by pre-generating one stack of Forte before Hiyuki’s Intro and using jump cancels to shave animation time. The problem shows up over a long fight, not in a single rotation. Because the cycle finishes early relative to the buff timers, the loop slowly desyncs and costs roughly 10 seconds of downtime by the fourth rotation.
4 Iai rotation: the recommended S0 Hiyuki loop
Four Iai is the version worth learning. The extra slash needs 100 more Frostheart than the baseline, which you generate with additional Foreclaimed Self normal attacks and a well-placed Frostblight cast rather than by standing still. In exchange, the cycle lands almost exactly on the 30-second mark, which is what keeps SuiSui’s buffs live across every repetition.
Note: holding Resonance Liberation instead of tapping puts Hiyuki into a charging pose that consumes Snowforged Blade one point at a time. The game is paused during that charge, so it does not eat into your clear time.
5 Iai rotation: highest damage, lowest margin for error
Five Iai is the ceiling. It needs 500 Frostheart across a single Foreclaimed Self window, which means near-perfect basic attack strings, jump cancels stitched between them, and no wasted frames anywhere in the combo. Every dropped input costs you the slash you were building toward.
The hard requirement is connection quality. High ping delays the basic attack and cancel timings enough that the chain breaks, and a broken chain here is worse than simply running the 4 Iai version from the start. Treat it as an optimization for controlled conditions rather than your everyday loop.
Team and build behind the comparison
The lineup is Hiyuki on Frostburn with Lucilla and SuiSui behind her, and SuiSui’s buff window is the timer everything is measured against. Hiyuki’s crit sits around 75.4% Crit Rate and 275.0% Crit DMG, with Lucilla near 77.2% and 272.6%. SuiSui runs a support profile instead, at 5.0% Crit Rate, 231.8% Crit DMG and 261.0% Energy Regen.
Frostburn matters more than the Iai count discussion suggests. It amplifies Glacio DMG when the wielder applies Glacio Chafe and makes Resonance Liberation damage ignore part of the target’s DEF, and almost everything Hiyuki throws in Foreclaimed Self counts as Resonance Liberation damage.
How to check the rotation is working
The clean confirmation is the Frostheart bar. If you finish your fourth Iai and the gauge reads zero right as Whiteout Bitterfrost hits 3 stacks, the loop is correct and the Bitterfrost heavy attack will be available immediately. Landing there with leftover Frostheart means you had room for another slash.
The most common reasons the chain stops early are mechanical. Iai Stance ends the moment Hiyuki is switched out, so any early swap kills the sequence. A follow-up Iai only becomes available when Frostheart is still at 100 or above after the previous one, and Iai Stance itself cannot be entered from Heavy Attack – Bitterfrost: Foreclaimed Self, Frostblight, another Iai, or the Intro Skill.
Swap timing is worth watching too, since a blocked switch at the end of the loop pushes your Outro past the buff window you just spent the whole rotation protecting.
Practice the 4 Iai loop until the dodge-into-stance timing is automatic, then decide whether your connection can support the fifth slash. For most S0 players it will not, and the two-second-longer four-slash cycle already gives you everything the buff window is paying for.
