Cinderella: Crystal WaveLimited

A limited Iron Code Pilgrim DPS and a top-tier main DPS candidate for Solo Raid and long single-boss fights.
She can switch between Machine Gun and Sniper modes herself to cover both core bosses and multi-part bosses alone, and her self-buffs and single-target Burst give her a high damage ceiling.
If you mainly run content where Iron is the weakness, she is well worth investing in.

When battle starts, she gains an attack damage buff and Pinpoint, which raises core damage. After a max-ammo reload finishes, reloading again in the switch-ready state changes her to Sniper mode; this turns on Pierce-oriented Destruction and a Damage to Parts buff, and removes Pinpoint. Finishing one more reload in Sniper mode returns her to Machine Gun mode.

Every 5 sec, fixed damage hits the enemy closest to the crosshair, and every time the squad consumes 200 rounds, her Burst Gauge is filled. Using her Burst Skill gives her attack damage and ATK buffs, and deals Burst Skill damage to the 1 enemy with the highest final ATK. At battle start and on Burst Skill use, a Decoy deploys, giving her room to last through longer fights.

If she used her Burst Skill right before Full Burst starts, she additionally deals AoE damage to all enemies in Sniper mode, or core strike damage to all enemies with exposed cores in Machine Gun mode.

For bosses where the core matters, keep Machine Gun mode as the default. Only when you need to hit parts directly, fire a few shots after a full reload, then reload again to switch to Sniper mode.
Sniper mode spends a lot of ammo per Full Charge, so time mode switches right after a reload finishes.
Auto can handle Machine Gun stretches, but choosing the right mode for each boss type is better done by hand.

Machine Gun reload and Max Ammo tie directly into her mode-switch rhythm, so prioritize Max Ammo and Reload cubes. If the cube level gap is large, use the higher-level Harmony Cube first regardless of ranking.

For the rest, add Max Ammo, Charge Damage, or Hit Rate based on weapon and mode choice. On bosses where you use Sniper mode often, Damage to Parts options are also a candidate.

Beauty-Full1 and Glass Slippers Full Contact WB determine her damage, so raise Skill 1 and Burst first. Mode Swap2's Decoy and mode-specific buffs run throughout the battle, so also raise Skill 2 even at the cost-efficient stage.

Use her as main DPS in stretches where you pound on a single boss for a long time, such as Solo Raid and Mirror Container. In Story stretches with frequent mobs, her single-target Burst and Machine Gun spread lower her priority.

Her single-target Burst and self-buffs give her high damage in boss fights.
Switching between Machine Gun and Sniper modes lets one unit cover both core bosses and parts bosses.
Her effect that Fills Burst Gauge based on ammo consumption helps Machine Gun squads.
Her Decoy gives survival leeway when fights drag on.

You need to time Sniper mode switches and reloads to reach her ceiling.
Her Burst is single-target, so her damage gets spread thin in mob-heavy fights.
Depending on Burst Skill timing, she may miss the Full Burst start buff.

She is often compared with Rapi: Red Hood for the same Burst 3 main DPS slot, and tends to hit a higher damage ceiling against single bosses weak to Iron. For bosses where splitting damage across parts matters, Sniper mode use and team choice vary.