Guide
How the kit works
Start with Wintertime Aria when available. It grants 30 Substance and 3 Moldable Crystals. Carlotta can hold 120 Substance and 6 Crystals. Art of Violence grants another 3 Crystals and inflicts Dispersion, immobilizing the target for 1.5 seconds.
Press the Skill again shortly afterward for Chromatic Splendor (skill). It consumes all Crystals and restores 10 Substance per Crystal. If you wait too long or switch Carlotta out, the Skill enters cooldown. You can also spend Crystals through Necessary Measures (basic): each strike consumes one and restores 10 Substance. A successful Dodge grants 3 Crystals, while a Dodge Counter consumes one.
At full Substance, Carlotta enters Final Bow, increasing the DMG Multiplier of her Liberation attacks by 80%. With Tinted Crystal active, hold Normal Attack to cast Imminent Oblivion (forte). It consumes Substance, deals Resonance Skill DMG and reduces the Skill cooldown by 6 seconds. Tinted Crystal activates every 22 seconds.
Cast Era of New Wave to inflict Deconstruction and enter Twilight Tango. Press Normal Attack or Liberation four times for Death Knell (liberation), then press again for Fatal Finale (liberation). Direct your movement during Death Knell to move with each shot. Twilight Tango ends after Fatal Finale; it removes Substance when it starts and ends.
Build and why
Use the recommended five-piece Frosty Resolve set. Its listed two-piece effect gives 12% Resonance Skill DMG, which fits much of Carlotta's kit. The supplied data does not describe its five-piece effect, so do not assume an extra bonus from it here.
The Last Dance is the first weapon choice. It gives 12% ATK and, after an Intro Skill or Liberation, 48% Resonance Skill DMG Bonus for 5 seconds. Keep that short duration in mind when planning your attacks.
Phasic Homogenizer is another strong option: it gives 12% ATK and, after a teammate uses Tune Break, grants its wielder 20% All-Attribute DMG Bonus for 14 seconds. Static Mist gives 12.8% Energy Regen, but its Outro effect boosts the incoming Resonator's ATK rather than Carlotta's.
For a 4-star option, consider Thunderbolt. Basic or Heavy Attack hits grant 7% Resonance Skill DMG Bonus per stack, up to three stacks, for 10 seconds. ATK is also worth considering when choosing stats: Carlotta's Outro damage explicitly scales with it.
Leveling priority
A suggested order is Lethal Repertoire, Era of New Wave, Art of Violence, Silent Execution, then Wintertime Aria. Start with Lethal Repertoire for Imminent Oblivion (forte), then focus on the Liberation sequence. The Skill comes next, followed by the Basic Attack used while building Substance.
For maximum character ascension, you need 170,000 Shell Credit, 4 LF Polygon Core, 12 MF Polygon Core, 12 HF Polygon Core, 4 FF Polygon Core, 46 Platinum Core and 60 Sword Acorus.
Maxing all skills takes 2,030,000 Shell Credit, 25 LF Polygon Core, 28 MF Polygon Core, 40 HF Polygon Core, 57 FF Polygon Core, 26 The Netherworld's Stare, 25 Impure Phlogiston, 28 Extracted Phlogiston, 55 Refined Phlogiston and 67 Flawless Phlogiston.
Resonance Chain nodes worth it
As a suggested high-investment target, As the Curtain Falls, I Remain What I Am (sequence 6) gives Death Knell (liberation) a total DMG Multiplier increase of 186.6% and doubles its crystal shards. Its Scattering effect immobilizes the target for up to 1.5 seconds, ending early if the target takes damage.
For an earlier upgrade, Beauty Blazes Brightest Before It Fades (sequence 1) is worth considering. Damage Carlotta deals to a target with Deconstruction gains 12.5% Crit. Rate for that instance. Chromatic Splendor (skill) also restores an extra 30 Substance when it hits a target with Dispersion.
Fallen Petals Give Life to New Blooms (sequence 2) is another suggested target, increasing Fatal Finale's DMG Multiplier by 126%. You can leave later nodes for another time if those effects are enough for your build. You cannot skip earlier nodes on the way to sequence 6.
Teams
Carlotta wants time on the field to build Substance and finish her Liberation sequence. Consider teammates who can support her Resonance Skill DMG, plus a defensive or healing option. Her kit does not state that she needs a particular teammate element.
Zhezhi is a Glacio teammate to consider, while Shorekeeper is a Spectro option. Lynae and Mornye are other named options. Their individual effects are not included in the supplied data, so check their in-game descriptions before deciding which support each slot provides.
Carlotta contributes damage when she leaves the field: Closing Remark deals Glacio DMG equal to 794.2% of her ATK. Her fourth sequence can also give the team Resonance Skill DMG Bonus after the specified Heavy Attacks.
Common mistakes
Do not start Liberation before filling Substance if you want Final Bow's damage multiplier increase. You cannot gain Substance or Crystals during Twilight Tango, and activating it removes your existing Substance.
Do not switch away in the middle of Twilight Tango if you want to finish the sequence with Final Bow active. Also watch the second Skill press: delaying it too long or switching out sends the Skill into cooldown.
Do not treat every Heavy Attack as Imminent Oblivion. It needs full Substance and an active Tinted Crystal. After Chromatic Splendor (skill), Flawless Purity protects Carlotta from damage and interruptions before her Mid-air Attack deals damage, so that is a useful window to use it.