Guide
How the kit works
Start with Suite of Quietus, then press Normal Attack to go straight to Basic Attack Stage 3. That attack and Whispers in a Fleeting Dream put Phrolova into Reincarnate. On the ground, follow either one with Normal Attack for Movement of Fate and Finality (forte), or with Resonance Skill for Murmurs in a Haunting Dream (forte). Both deal damage counted as Resonance Skill DMG.
With six notes, Compose ready and no Resolving Chord active, use Scarlet Coda (basic). It pulls and Stagnates targets, counts as Resonance Skill DMG and as casting an Echo Skill, and starts Resolving Chord. Compose becomes available every 25 seconds.
Resolving Chord unlocks Waltz of Forsaken Depths. Cast it to enter Maestro for 24 seconds and gain 120% ATK. Hecate plays the notes in order, each for four seconds: Strings Stagnates, Winds pulls, and Cadenza does both on the corresponding enhanced attack. On field, two basic Hecate attacks make the next one enhanced. Off field, teammates' Echo Skills trigger enhanced attacks, up to 10 times; an Echo of the same name can trigger one only once.
Build and why
Dream of the Lost is the first set to consider from the guide evidence. Havoc Eclipse is another option: its two-piece bonus gives 10% Havoc DMG, matching Phrolova's element. The effects of Dream of the Lost and the larger Havoc Eclipse set are not provided here, so check them in game before committing.
The game's build lists five-piece Flaming Clawprint, but the supplied two-piece effect gives Fusion DMG, not Havoc DMG. Its five-piece effect is not provided, so that recommendation cannot be assessed from the available details.
Lethean Elegy is the first weapon choice. After Echo Skill DMG, it gives Resonance Skill DMG Bonus and Echo Skill DMG Amplification, both useful to her kit. Stringmaster follows: it gives Attribute DMG Bonus, gains ATK from Resonance Skill DMG and adds ATK while its wielder is off field. Whispers of Sirens is another listed option, though its known one-stack bonus favors Basic Attack DMG and its stack effect ends on switching.
ATK and Crit. DMG are stats worth considering. Hecate shares Phrolova's stats, and Octet raises Crit. DMG as she gains Aftersound.
Leveling priority
As a leveling suggestion, start with Rhapsody of a New World, then Waltz of Forsaken Depths. The Forte contains the enhanced follow-ups used to build notes, while the Liberation contains Hecate's attacks. Next, consider Movement of Life and Death for Scarlet Coda, followed by Whispers in a Fleeting Dream and Suite of Quietus.
For maximum ascension, gather Shell Credit, LF Polygon Core, MF Polygon Core, HF Polygon Core, FF Polygon Core, Truth in Lies and "Afterlife". Skill upgrades also use Shell Credit and the Polygon Cores, plus The Netherworld's Stare, Lento Helix, Adagio Helix, Andante Helix and Presto Helix.
Resonance Chain nodes worth it
For Resonance Chain upgrades, a suggested order to consider is A Dagger to Cut Clean Obsessions (sequence 3), A Rope Tied to a Life Beyond (sequence 2), then A Night to Depart From Eternal Rest (sequence 6). The third node amplifies Echo Skill DMG by 80% and converts the notes to Cadenza in turn when you cast Scarlet Coda (basic). Hits from the corresponding enhanced attack also reduce enemy ATK by 20% for 15 seconds.
The second node increases Scarlet Coda's damage multiplier and grants 14 Aftersound stacks when you cast it. The sixth adds an Echo Skill DMG attack to the two enhanced follow-ups. During Maestro, it also gives 60% Havoc DMG Bonus on field, or makes targets take 40% more damage from Hecate and Phrolova while she is off field.
A Key to Netherworld's Secrets (sequence 1) improves the two follow-ups and can provide starting notes after four seconds out of combat. A Torch Illuminating the Path (sequence 4) gives the team Attribute DMG Bonus after an Echo Skill. A Forked Road in Fate's Heartland (sequence 5) adds Stagnation and damage reduction during Maestro; if you do not want the sixth node, stopping before the fifth is an option.
Teams
Pair Phrolova with someone who can take field time while Hecate attacks. Different Echo names matter in that window because each name can trigger only one enhanced Hecate attack off field. A healer is also worth considering for the team.
Unfinished Piece gives the incoming Resonator 20% Havoc DMG Amplification and 25% Heavy Attack DMG Amplification for 14 seconds, ending early if that Resonator switches out. A Havoc damage dealer who uses Heavy Attacks can use both bonuses. If Phrolova uses her Outro during Maestro, Hecate also performs two extra enhanced attacks in that Maestro duration.
Rover: Havoc, Cantarella and Danjin are Havoc teammates named in the guide evidence. Qiuyuan and Shorekeeper are other named options. Check their own kits when choosing who takes the field after Phrolova.
Common mistakes
Do not switch straight back to Phrolova if you want Hecate to keep attacking off field. Returning ends Maestro and removes the notes. While Phrolova is on field in that state, dodge for Hecate: damage Hecate takes affects Phrolova too.
Do not build around Basic Attack DMG alone. Scarlet Coda counts as Resonance Skill DMG, while Hecate's attacks count as Echo Skill DMG. Also remember that Phrolova's maximum Resonance Energy is zero, so her Liberation does not consume it.
