Guide
How the kit works
Start with Cleaning Mode: Carrier Frequency. It deals AoE Electro DMG, creates an Optical Flow Shield Barrier and summons Birgitta. The shield's absorption scales with Ineffa's ATK and is 250% effective against Electro DMG.
Use Supreme Instruction: Cyclonic Exterminator when available. It deals AoE Electro DMG and leaves Birgitta on the field. If she is already there, the Burst summons her again at the target's location and resets her duration. It also gives Ineffa and your active character Elemental Mastery equal to 6% of Ineffa's ATK for 20 seconds.
Bring Hydro into the team to trigger Electro-Charged and let Ineffa convert it. When Birgitta uses a Discharge attack near a thundercloud made by Lunar-Charged, she makes an extra AoE Electro attack equal to 65% of Ineffa's ATK. This counts as Lunar-Charged DMG.
Cyclonic Duster (NA) has up to four spear strikes. Its Charged Attack costs Stamina, while the Plunging Attack deals AoE DMG on impact. These attacks are available when Ineffa is on the field, but the shield and Birgitta do not require you to keep attacking with her.
Build and why
Use four pieces of Aubade of Morningstar and Moon for Ineffa's own Lunar Reaction damage. While she is off-field, the set increases that damage by 20%, with another 40% at Ascendant Gleam. The effect disappears after she has been active for 3 seconds, so pay attention to her field time.
Silken Moon's Serenade is a team-oriented alternative. Its four-piece effect gives the party 60 or 120 Elemental Mastery according to Moonsign level and can trigger off-field. Gilded Dreams is another option: after a reaction, it gives ATK for teammates of the same element and Elemental Mastery for those of a different element. The game's suggested two-piece combination is Gladiator's Finale plus Wanderer's Troupe, for 18% ATK and 80 Elemental Mastery.
Choose ATK Percentage on the sands and goblet, then CRIT Rate or CRIT DMG on the circlet. For substats, the game's order is CRIT Rate, CRIT DMG, ATK Percentage, then Elemental Mastery. ATK helps the shield and several passives, while the CRIT stats support Ineffa's damage.
Fractured Halo is the first weapon to consider. After a Skill or Burst it grants 24% ATK for 20 seconds; creating a shield while that effect is active grants nearby party members 40% more Lunar-Charged DMG. Staff of the Scarlet Sands converts Elemental Mastery into ATK and gains further conversion stacks when the Skill hits. Missive Windspear is another option, giving ATK and Elemental Mastery after an Elemental Reaction.
For a different four-star option, Prospector's Shovel directly increases Lunar-Charged DMG, with a further increase at Ascendant Gleam.
Leveling priority
A sensible talent order is Cleaning Mode: Carrier Frequency, then Supreme Instruction: Cyclonic Exterminator, and finally Cyclonic Duster (NA). Start with the Skill for its shield and Electro hit, then raise the Burst for its AoE hit. Normal Attacks can wait if you mostly switch away after setting up Birgitta.
For ascension, gather Glowing Hornshroom and Secret Source Airflow Accumulator, along with Vajrada Amethyst Sliver, Vajrada Amethyst Fragment, Vajrada Amethyst Chunk and Vajrada Amethyst Gemstone. You also need Sentry's Wooden Whistle, Warrior's Metal Whistle, Saurian-Crowned Warrior's Golden Whistle and Mora.
Constellations worth it
Rectifying Processor is the standout upgrade. Creating Ineffa's shield gives nearby party members Lunar-Charged DMG for 20 seconds: 2.5% per 100 ATK, up to 50%.
A Dawning Morn for You adds an AoE Electro hit worth 135% of Ineffa's ATK after nearby thunderclouds release lightning, provided Ineffa has the effect from C1. It counts as Lunar-Charged DMG and can trigger once every 3.5 seconds.
Support Cleaning Module is worth considering for another Lunar-Charged hit after the Burst connects. It also gives nearby party members shields when the Burst is used. Enhanced Emotion Emulator and Mirror's Dream Transcension raise talent levels, so you can leave them aside if you are interested in new effects rather than level increases.
Common mistakes
Do not build around Lunar-Charged and then leave Hydro out of the team. Ineffa's conversion needs a party member to trigger Electro-Charged first.
Do not assume that Ineffa's extra Moonsign level always gives Ascendant Gleam. Check the party's level before counting on the larger bonus from Aubade of Morningstar and Moon or Silken Moon's Serenade.
Do not ignore ATK when choosing artifacts: it affects shield absorption, the Burst's Elemental Mastery buff and the Lunar-Charged Base DMG passive. If you use Aubade of Morningstar and Moon, avoid keeping Ineffa active long enough to lose its off-field effect.
