Guide
How the kit works
Start with Framing: Freezing Point Composition. A tap deals AoE Cryo damage in front of Charlotte and applies Snappy Silhouette to up to five opponents. The mark deals Cryo damage at intervals.
Holding the Skill opens a viewfinder. Charlotte can move and turn while it expands, and you can lock on to up to five opponents. Release after reaching Finisher Frame to apply Focused Impression instead: it lasts longer and deals more damage, but gives the Skill a longer cooldown. Defeating opponents with that mark reduces the cooldown by 2 seconds per opponent, up to four times every 12 seconds.
Follow with Still Photo: Comprehensive Confirmation when the party needs healing. Its Newsflash Field damages opponents inside it and heals the active character there. Cool-Color Capture (NA) is available when Charlotte needs to attack on field, but her Skill and Burst do most of the work in a support build.
Activating the Special Analysis Zoom Lens changes the held Skill into a photo mode and prevents its original effects. Turn it off when you want to mark enemies in combat.
Build and why
Use four pieces of Noblesse Oblige for team support. Its Burst bonus helps Charlotte deal damage, and using her Burst gives the whole party 20% ATK for 12 seconds. The four-piece effect cannot stack.
Tenacity of the Millelith is another option: Skill hits give nearby party members 20% ATK and 30% Shield Strength for 3 seconds. Ocean-Hued Clam instead turns recorded healing into damage. Song of Days Past is worth considering if you want healing to increase the active character's damage. For a mixed set, two pieces of Emblem of Severed Fate and two of Gladiator's Finale give Energy Recharge and ATK.
On the sands, choose Energy Recharge or ATK Percentage. Use ATK Percentage on the goblet, and Healing Bonus, ATK Percentage or CRIT Rate on the circlet. Look for Energy Recharge first in substats, followed by ATK Percentage, CRIT Rate and ATK. ATK improves her healing; CRIT Rate helps with Favonius Codex.
Prototype Amber is the first weapon choice: after a Burst, it restores Energy to Charlotte and heals the party every 2 seconds for 6 seconds. Favonius Codex is next; its CRIT Hits can generate particles that restore Energy. Thrilling Tales of Dragon Slayers gives the character you switch to 24% ATK for 10 seconds. Oathsworn Eye is another option, granting Energy Recharge after a Skill.
Leveling priority
For a healing build, I suggest leveling Still Photo: Comprehensive Confirmation first because it contains both the party-wide heal and the field's ongoing healing. Level Framing: Freezing Point Composition next for its damage. Leave Cool-Color Capture (NA) until last if Charlotte rarely attacks on field.
For maximum ascension, you need 420,000 Mora, 168 Beryl Conch, 1 Shivada Jade Sliver, 9 Shivada Jade Fragment, 9 Shivada Jade Chunk and 6 Shivada Jade Gemstone. You also need 18 Meshing Gear, 30 Mechanical Spur Gear, 36 Artificed Dynamic Gear and 46 "Tourbillon Device".
Maxing all three skills takes another 4,957,500 Mora, 3 Crown of Insight, 9 Teachings of Justice, 63 Guide to Justice, 114 Philosophies of Justice and 18 Lightless Silk String. It also takes 18 Meshing Gear, 66 Mechanical Spur Gear and 93 Artificed Dynamic Gear.
Constellations worth it
For a healer, I'd look at A Need to Verify Facts first. After the Burst heals a character, Verification heals them every 2 seconds for 6 seconds. Each tick is based on 80% of Charlotte's ATK, giving the team more healing after the initial cast.
A Responsibility to Oversee is another upgrade to consider. When the Burst hits a marked opponent, it deals 10% more damage and restores 2 Energy to Charlotte. The Energy restoration can trigger five times every 20 seconds.
A Summation of Interest adds a coordinated Cryo attack when the active character's Normal or Charged Attack hits an opponent with Focused Impression. It also heals active characters in the area, and can trigger once every 6 seconds. It needs the held Skill's longer mark, so it is less useful if you usually tap the Skill.
A Duty to Pursue Truth gives Charlotte ATK based on how many opponents her Skill hits, while An Imperative to Independence raises her Burst level. A Principle of Conscience raises her Skill level instead. You can do without these upgrades if the base kit already covers your needs.
Teams
Charlotte fits a team that wants healing and repeated Cryo damage. Try her with Furina and a Cryo teammate such as Kamisato Ayaka or Wriothesley. Hydro and Cryo give you a Freeze option, while Kaedehara Kazuha can fill an Anemo Swirl slot.
Her passive changes its bonus with the party's origins: one, two or three Fontainian teammates give her 5%, 10% or 15% Healing Bonus. The same counts of non-Fontainian teammates give her 5%, 10% or 15% Cryo DMG Bonus. Choose the team around the roles you need rather than treating either bonus as a requirement.
Common mistakes
Do not build only ATK and neglect Energy Recharge. Charlotte's party heal is on her Burst, so you need to be able to use it when the team needs it. With Favonius Codex, do not ignore CRIT Rate either: the weapon's particle effect requires a CRIT Hit.
Do not hold the Skill automatically in every situation. Focused Impression lasts longer, but its cooldown is longer too; a tap is useful when you want a quicker mark. After using the Burst, keep the active character inside its field if you need the ongoing healing. Also check the Special Analysis Zoom Lens if holding the Skill takes a photo instead of marking opponents.
