Guide
How the kit works
Start with Intro Skill - Solsworn Etymology, then press Normal Attack to continue at Basic Attack Stage 2. You can also use the regular Resonance Skill and follow it with Normal Attack to reach Stage 3. Stage 4 of One, Two, Three puts Sigrika into Decipher for 5 seconds.
In Decipher, Basic Attack - Elucidated (basic) gives a Rune: Trust when it hits directly. The enhanced Resonance Skill gives a Rune: Answer instead. At 50 or more Full Stop, use Resonance Skill - Soliskin to the Aid (skill) for a Rune: Answer. Each choice ends Decipher.
True Names Invoked gives Convergent on Intro: the next Rune also creates one of the same type. Resonance Liberation grants Divergent, which instead creates an opposite Rune. Convergent takes priority if both are present, and neither effect works at 100 Full Stop.
Hold Normal Attack to spend two Runes on Heavy Attack - Schemata of Runes (forte). Two Trust Runes Stagnate nearby targets; two Answer Runes pull them in. A mixed pair produces Runic Outburst. With at least 30 Soliskin Vitality, the attack consumes 30, increases the resulting Runic attack's damage multiplier by 50% and grants Innate Gift?.
Each Schemata of Runes grants 50 Full Stop. At 100, hold Resonance Skill to cast Forte Circuit - Learn My True Name (forte). Innate Gift? boosts its damage and the Runic attacks, but disappears after this finisher or when Sigrika leaves the field.
Build and why
Use five pieces of Sound of True Name, the set recommended for this build. Its two-piece bonus gives 10% Aero DMG. The supplied data does not describe its five-piece effect. Sierra Gale is an alternative worth considering for its two-piece 10% Aero DMG bonus; its remaining effect is not specified here either.
Solsworn Ciphers is the first weapon choice. Its ATK increase helps Sigrika, while an Intro or Echo Skill grants Echo Skill DMG Amplification. Dealing Echo Skill DMG also makes Aero DMG ignore some target DEF.
Blazing Justice is the next option: it increases ATK and lets damage ignore DEF after a Basic Attack. Pulsation Bracer follows, with ATK and a conditional Basic Attack DMG Bonus against targets under Tune Strain - Interfered. Check that condition rather than assuming its full effect is always active.
Abyss Surges offers Energy Regen, while Celestial Spiral is a four-star option that restores Resonance Energy and increases ATK after Resonance Skill. Energy Regen has another use through True Names Aligned: each 1% above 125% grants 2% Echo Skill DMG Bonus, up to 50%.
Leveling priority
A suggested order is Forte Circuit first, then Resonance Liberation, Resonance Skill, Basic Attack and Intro Skill. Within Infinity's Embrace contains the Rune attacks and Full Stop finisher that drive her field time. Where Trust Leads Me! also deals Echo Skill DMG, while the skill and basic attacks help generate Runes.
For maximum ascension, gather Shell Credit, the Fractured Exoswarm Pendant, Worn Exoswarm Pendant, Chipped Exoswarm Pendant and Intact Exoswarm Pendant materials, plus Our Choice and Arithmetic Shell.
Skill upgrades also use Shell Credit and the four Exoswarm Pendant materials, as well as Gold in Memory, LF Waveworn Shard, MF Waveworn Shard, HF Waveworn Shard and FF Waveworn Shard.
Resonance Chain nodes worth it
For a long-term progression goal, True Names Resurfaced, Rising in Light (sequence 6) is worth considering. Targets take 30% more damage from Sigrika, and Innate Gift? adds damage amplification and DEF ignore to her Runic attacks and finisher.
I Flee, Yet I Seek (sequence 3) is another attractive upgrade: Innate Gift? can reach four stacks and no longer disappears after the finisher or a switch. The Bitterness Steeped in Hope (sequence 2) increases the finisher's damage multiplier by 120%.
If you are stopping before sequence 6, sequences 4 and 5 are reasonable places to stop rather than pursue further upgrades. I Lose, Yet I Gain (sequence 4) gives the team ATK after an Echo Skill; Until Submerged by the Dark (sequence 5) increases the Liberation's damage multiplier.
Teams
Bring teammates who can cast Echo Skills. Each differently named Echo grants Sigrika 10 Soliskin Vitality and a stack of Blessing of Runes. At six stacks, the active Resonator gets 18% Aero DMG Bonus and 18% Echo Skill DMG Bonus, while Sigrika gains further bonuses.
Outro Skill - In This Very Moment deals Aero DMG equal to 795% of Sigrika's ATK and gives two Encapsulated stacks for 30 seconds. Nearby team Echo Skills consume those stacks to Stagnate the target.
Common mistakes
Do not switch Sigrika out while preparing Decipher or holding Innate Gift?: both end when she leaves the field. Use the finisher before switching if you want to keep that damage amplification.
Do not spend Runes without looking at Soliskin Vitality. At 30 points, you gain the stronger multiplier increase and an Innate Gift? stack. Below 30, all remaining Vitality is consumed instead, granting 15% damage amplification for every 10 points spent.
Do not rely on the same Echo name repeatedly for every stack. In This Very Moment resets the Echo record for Soliskin Vitality, but Blessing of Runes resets on a lineup change.