Guide
How the kit works
Start in Stagecraft Form with Formal Greetings. Its Stagecraft attack grants a Dark Core and 25 Void Particle; a Normal Attack after it goes straight to Stage 4. Stagecraft Normal Attacks also build Void Particle, while Phantom Bubble - Stagecraft Form (Skill) pulls enemies in and grants another 25 points.
Cast Final Act - Stagecraft Form (Liberation) to deal Fusion DMG and switch to Breakdown Form. You gain Entropy Shift: Breakdown Form for 12 seconds, with 30% increased ATK. In Breakdown Form, Normal Attacks consume Void Particle on hit: their damage counts as Resonance Liberation DMG, their multiplier rises by 50%, and Conformal Charge regenerates 100% faster.
While holding a Dark Core, Banish - Breakdown Form (Skill) replaces Beckon - Breakdown Form (Skill). Its first stage pulls enemies in; press Normal Attack or Resonance Skill shortly afterward for the second stage. That consumes all Dark Cores, adding 150% to its damage multiplier per Core, and grants 40 Conformal Charge. Denia can normally hold three Cores.
Once Conformal Charge is full, cast Final Act - Breakdown Form (Liberation). It consumes all Conformal Charge and Void Particle, switches Denia back to Stagecraft Form and grants Entropy Shift: Stagecraft Form for 30 seconds. That state grants one Void Particle per second. The Liberation also creates an Erosion Field for 30 seconds, pulling nearby targets and dealing Fusion DMG every four seconds.
In Fusion Burst mode, selected attacks apply Fusion Burst. In Tune Strain mode, those attacks instead inflict Tune Strain - Shifting and reset the target's Tune Strain - Interfered duration. When a Resonator in the team inflicts Shifting, the target gains 50% of its maximum Off-Tune Level, once per target every 300 seconds.
Build and why
The game recommends five pieces of Chromatic Foam or Reel of Spliced Memories. Chromatic Foam comes first: its two-piece bonus gives 10% Fusion DMG, matching Denia's attacks. Reel of Spliced Memories is the alternative, with 10% ATK from two pieces. The available data does not describe either five-piece effect.
Forged Dwarf Star is the first weapon choice. It gives 12% ATK and, after the wielder inflicts Fusion Burst or Tune Strain - Shifting, 36% Resonance Liberation DMG Bonus for five seconds. During that effect, team members who inflict either status gain 24% ATK for 15 seconds.
Stringmaster is the next option: it gives 12% Attribute DMG Bonus and can build ATK stacks by dealing Resonance Skill DMG. Lethean Elegy follows, with 12% ATK and bonuses after Echo Skill DMG, including 8% DEF ignored when dealing damage. Remember that Banish deals Resonance Liberation DMG, so a Resonance Skill DMG bonus does not match that attack's damage type.
Leveling priority
A suggested skill order is Final Act, “Flawless” (Forte), Bubbles and Baits, Dreamweaver's Banquet, then Formal Greetings. The Liberation is central to switching forms and creating the field, while the Forte covers resources and mode effects. The Skill includes Banish, and Basic Attacks are used in both forms. The data does not give an improvement-by-level breakdown, so treat this as a starting order.
For maximum ascension, collect 170,000 Shell Credit, 4 LF Mech Core, 12 MF Mech Core, 12 HF Mech Core, 4 FF Mech Core, 46 Burning Judgment and 60 Dream of Stars.
For all skills, collect another 2,030,000 Shell Credit, 25 LF Mech Core, 28 MF Mech Core, 40 HF Mech Core, 57 FF Mech Core, 26 We Who Question, 25 Spliced String, 28 Broken String, 55 Solidified String and 67 Melodic String.
Resonance Chain nodes worth it
As a suggested ranking of the biggest upgrades, May You Find Your Sun in the Silence (Sequence 6) comes first. During Entropy Shift it gives Denia 60% ATK and 60% Fusion DMG Bonus. It also adds a mode-specific effect: Erosion Field can trigger Fusion Burst without removing its stacks, or team Tune Break DMG can add Tune Strain - Interfered under the stated conditions.
Through Dark and Wind, the Erlking Follows (Sequence 3) is next. It raises the Breakdown Form Liberation's damage multiplier by 80%, increases the Dark Core limit to five and improves resource generation. It also restores 30 Concerto Energy when that Liberation is cast.
Tossed in the Tides of Reality (Sequence 2) is worth considering for its team and mode bonuses. In Fusion Burst mode it gives a teammate who inflicts Fusion Burst 50% Fusion DMG Bonus for 15 seconds. In Tune Strain mode it increases Tune Break Boost and can fill a target's Off-Tune Level, subject to a 300-second per-target limit.
Silent Glows in a Dimlit Dream (Sequence 1) adds 30% Crit. DMG and interruption immunity during specified attacks. From the Far Beyond, to the Far Beyond (Sequence 4) shortens the Erosion Field interval, while If Lies Patch Up a Heart (Sequence 5) increases Stagecraft Form Liberation damage. You can stop before the later Sequences if their effects are not your priority.
Teams
For Tune Strain mode, consider a teammate who can inflict Tune Strain - Shifting. The incoming Resonator gets 15% All DMG Amplification for 16 seconds, rising to 40% instead after they inflict Shifting under that effect. It ends early if they switch out or Denia changes modes. Qingxiao is another teammate named by a guide.
Etched Colors gives the whole team 30% Fusion DMG Bonus during Entropy Shift in Fusion Burst mode. In Tune Strain mode it gives 10 Tune Break Boost, with more available based on a Resonator's Off-Tune Buildup Rate above 100%. A sustain character is a reasonable third-slot consideration; Shorekeeper is among the guide-named options.
Common mistakes
Do not leave Breakdown Form resources unused. Build Conformal Charge, follow the first stage of Banish - Breakdown Form (Skill) with its second stage, and cast Final Act - Breakdown Form (Liberation) when Charge is full. Remember that the Liberation consumes remaining Void Particle too.
Do not expect every attack to apply your mode's status. The listed attacks have a per-skill, per-target two-second limit. Shattered Hours requires a full Off-Tune Level before Denia can cast Tune Break.
Do not switch modes carelessly after Unfinished Lies: its team effect ends early. In Tune Strain mode, switching the incoming Resonator out also ends their amplification.
