Guide
How the kit works
Start with As the Sunlit Sky's Singing Salute when it is available. Its initial bombardment deals AoE Geo DMG, then Cannon Fire Support periodically attacks nearby opponents. Cannon hits grant one Crystal Shrapnel stack, at most once every 2.4 seconds.
Collect Elemental Shards from Crystallize or trigger Lunar-Crystallize to gain more stacks. Navia can hold six, and gaining a stack refreshes the duration of those already held. Lunar-Crystallize can grant at most one stack per second.
Use Ceremonial Crystalshot after building stacks. It consumes all of them: zero, one, two or at least three stacks produce five, seven, nine or eleven Rosula Shardshots. If all eleven hit one opponent, the attack deals 200% of its original damage. Each stack beyond three adds another 15%. Hold the skill to aim and collect nearby Crystallize shards before releasing it. The skill has two initial charges.
After firing, use Blunt Refusal (NA). Undisclosed Distribution Channels converts Navia's Normal, Charged and Plunging Attacks to Geo for four seconds and increases their damage by 40%. The infusion cannot be overridden by another Elemental infusion.
Build and why
Use four pieces of Nighttime Whispers in the Echoing Woods. After an Elemental Skill, it gives 20% Geo DMG Bonus for 10 seconds. A Crystallize shield or nearby Lunar-Crystallize Moondrifts increase that effect by 150%. The two-piece bonus also gives 18% ATK.
Marechaussee Hunter is an alternative if the team changes Navia's HP: each HP increase or decrease gives 12% CRIT Rate for five seconds, up to three stacks. Golden Troupe is another option for Elemental Skill damage. You can also pair two pieces of Golden Troupe with two pieces of Archaic Petra for Skill DMG and Geo DMG Bonus.
Consider four pieces of A Day Carved From Rising Winds for its ATK bonus after attacks hit. Its extra CRIT Rate requires Witch's Homework to be completed.
For main stats, use ATK Percentage on the sands, Geo DMG Bonus or ATK Percentage on the goblet, and CRIT Rate or CRIT DMG on the circlet. Look for CRIT Rate, CRIT DMG and ATK Percentage in substats, followed by Energy Recharge and ATK.
Verdict is the first weapon choice: its Seals increase Elemental Skill damage when the party collects Crystallize shards or triggers Lunar-Crystallize. Serpent Spine is a 4-star alternative that builds damage while Navia is on field, though taking damage removes a stack. A Thousand Blazing Suns gives CRIT DMG and ATK after a Skill or Burst; her infused attacks can extend that effect.
Leveling priority
A good leveling order is Ceremonial Crystalshot, then Blunt Refusal (NA), then As the Sunlit Sky's Singing Salute. The Skill is the main shot, while Normal Attacks make use of the Geo infusion after it. The Burst still contributes damage and helps build stacks.
For maximum ascension, gather 420,000 Mora, 168 Spring of the First Dewdrop, one Prithiva Topaz Sliver, nine Prithiva Topaz Fragment, nine Prithiva Topaz Chunk, six Prithiva Topaz Gemstone, 18 Transoceanic Pearl, 30 Transoceanic Chunk, 36 Xenochromatic Crystal and 46 Artificed Spare Clockwork Component — Coppelius.
To raise all skills to their maximum, you need 4,957,500 Mora, three Crown of Insight, nine Teachings of Equity, 63 Guide to Equity, 114 Philosophies of Equity, 18 Transoceanic Pearl, 66 Transoceanic Chunk, 93 Xenochromatic Crystal and 18 Lightless Silk String.
Constellations worth it
I would consider The Flexible Finesse of the Spina's President the biggest damage upgrade. Each stack consumed beyond the first three adds 45% CRIT DMG to that shot, and those extra stacks are returned.
The President's Pursuit of Victory is another strong option. Each consumed stack adds 12% CRIT Rate to the shot, up to 36%. A Skill hit also calls one Cannon Fire Support shot, whose damage counts as Elemental Burst damage.
The Oathsworn Never Capitulate is worth considering for its 20% Geo RES reduction for eight seconds when the Burst hits. A Lady's Rules for Keeping a Courteous Distance instead restores up to nine Energy and reduces the Burst cooldown by up to three seconds per Skill use. You can skip C1 if you do not need that help; C3 and C5 are level increases rather than new effects.
Teams
Bring characters who can help generate Crystallize shards or trigger Lunar-Crystallize. Mutual Assistance Network gives Navia 20% ATK for each Pyro, Electro, Cryo or Hydro teammate, up to two teammates. Two such party members give her the full 40%.
Common mistakes
Do not fire every shot with no stacks by habit. Three stacks produce the maximum number of Rosula Shardshots, and stacks beyond three add damage. You do not always need to wait for six, but check what you have before using a charge.
Do not aim so far away that too many Rosula Shardshots miss the same target. Hold Ceremonial Crystalshot when you need to aim or pick up nearby Crystallize shards, then release it at the opponent.
Do not ignore your attacks after the Skill: the Geo conversion and damage increase last only four seconds. Also watch your weapon and artifact conditions. Serpent Spine loses a stack when you take damage, while Nighttime Whispers in the Echoing Woods needs a Crystallize shield or nearby Lunar-Crystallize Moondrifts for its increased bonus.
