Guide
How the kit works
Start with Instant of Annihilation when it is available. It deals Havoc damage and recovers Umbra. Use Tuneslayer and Wingblade (E) to build more Umbra. Tuneslayer has up to five Basic Attacks, and a Basic Attack after a regular Heavy Attack goes straight to attack four.
Umbra Eclipse holds up to 100 Umbra. When the gauge is full, hold Basic Attack to cast Devastation. It deals Heavy Attack damage and puts you in Dark Surge. Your Basic and Heavy Attacks are enhanced, and Wingblade becomes Lifetaker (E), which also recovers Umbra.
In Dark Surge, use Basic Attack after Enhanced Heavy Attack for Thwackblade, then use Basic Attack again to reach Enhanced Basic Attack 3. Metamorph (Passive) gives you 20% Havoc DMG Bonus in this state. Bleak Crescendo makes Basic Attack hits restore 1 extra Resonance Energy, up to once per second.
Use Deadening Abyss (Ult) to deal Havoc damage. When you use Soundweaver, its field deals Havoc damage equal to 143.3% of ATK every 2 seconds for 6 seconds to targets in range.
Build and why
The game's build recommends five pieces of Havoc Eclipse. Its listed two-piece effect gives 10% Havoc DMG, which suits a kit that deals Havoc damage throughout. The five-piece effect is not supplied here, so don't assume what it does. Two pieces of Lingering Tunes give 10% ATK and are an option alongside two pieces of Havoc Eclipse.
Emerald of Genesis is the first weapon choice. It gives 12.8% Energy Regen, and casting Resonance Skill gives 6% ATK per stack, up to two stacks for 10 seconds. Both versions of your Resonance Skill fit that trigger.
Commando of Conviction gives 15% ATK for 15 seconds after an Intro Skill. Lumingloss is another option: casting Resonance Skill gives 20% Basic Attack DMG Bonus and Heavy Attack DMG Bonus for 10 seconds. That matches your attacks in Dark Surge, including Devastation and Thwackblade.
ATK and Havoc DMG Bonus are reasonable stats to consider: Soundweaver (Outro) scales with ATK, and your damage is Havoc. Energy Regen is also worth considering, though the supplied build does not give a stat priority.
Leveling priority
A suggested leveling order is Umbra Eclipse, Deadening Abyss (Ult), Tuneslayer, Wingblade (E), then Instant of Annihilation. Start with the Forte because it contains Devastation and the Dark Surge attacks. The Liberation gives you another Havoc attack, while Basic Attacks help fill Umbra and remain part of the Dark Surge rotation. This is a suggestion, not a supplied game order.
For maximum ascension, you need 170,000 Shell Credit, 4 LF Whisperin Core, 12 MF Whisperin Core, 12 HF Whisperin Core, 4 FF Whisperin Core, 5 Mysterious Code and 60 Pecok Flower.
For all skills, you need 2,030,000 Shell Credit, 25 LF Whisperin Core, 28 MF Whisperin Core, 40 HF Whisperin Core, 57 FF Whisperin Core, 26 Dreamless Feather, 25 Inert Metallic Drip, 28 Reactive Metallic Drip, 55 Polarized Metallic Drip and 67 Heterized Metallic Drip.
Resonance Chain nodes worth it
For Resonance Chain upgrades, I would put Ebbing Undercurrent (Sequence 6) first: it gives 25% Crit. Rate in Dark Surge. Annihilated Silence (Sequence 4) is another option to consider. Devastation and Deadening Abyss (Ult) reduce the target's Havoc RES by 10% for 20 seconds on hit, which can also help teammates dealing Havoc damage.
Waning Crescent (Sequence 2) is worth considering for its Resonance Skill cooldown reset when Devastation puts you in Dark Surge. Cryptic Insight (Sequence 1) raises Resonance Skill DMG Bonus by 30%.
Surging Resonance (Sequence 3) restores HP equal to 10% of total HP lost when Basic Attack 5 hits in Dark Surge. Aeon Symphony (Sequence 5) adds Havoc damage equal to 50% of that attack's damage. If you don't need the healing, Sequence 3 is a less appealing stopping point; Sequence 5 is optional if you aren't aiming for Sequence 6.
Teams
A healer and a teammate who can support your damage are reasonable roles to look for. The teammate evidence names Roccia, Sanhua, Verina and Shorekeeper as options, but it does not describe their skills, so check their kits before choosing the jobs you need.
Common mistakes
Don't hold Basic Attack expecting Devastation before Umbra reaches 100. Build the gauge with your attacks and Resonance Skill first. Once in Dark Surge, remember the Basic Attack follow-up after Enhanced Heavy Attack rather than treating the two states as the same rotation.
Don't assume the five-piece Havoc Eclipse effect from its two-piece bonus. Also check how much Crit. Rate you have if you use Ebbing Undercurrent (Sequence 6): its 25% increase applies in Dark Surge, not in every state.
