Alice

A Burst 3 Fire Sniper Rifle who works as a top-tier main DPS in story, Tower, and campaign.
She was once a Nikke whose impact grew greatly with investment, but recent boss design and firepower competition have narrowed her role as a main Raid and boss pick.
If you have built her, she is still used in Tetra Tower. The early-game Alice Diary quests raise her to a decent level, so she is useful in the early game too.

At 80% HP or more she gains Pierce, and when HP falls below that she sustains with healing based on damage dealt. When Full Burst starts, the two allies with the highest ATK get Charge Speed and Charge Damage multiplier. Using her Burst Skill briefly concentrates Charge Speed and Increased ATK on herself, spiking her single-target firepower.

Fire after a Full Charge, and during Burst cut charge intervals short to rapid-fire.
Keep HP at 80% or more to keep Pierce active.
Auto is fine by default, but manual is better for Charge and tap-firing tempo.

To match Pierce, the Piercing Cube comes first. Cover Burst rapid fire and reload with the Resilience Cube, and Charge support with the Wingman Cube. If your Overload has many Max Ammo lines, lean more on the Resilience Cube. If Harmony Cube levels differ a lot, use the higher-level cube before the ranking.

The target build is 4 lines of Elemental Advantage damage, 4 lines of ATK, 2 lines of Max Ammo, and 2 lines of Charge Speed. Priority is Charge Speed (2 lines, 8.18% or more), Elemental Advantage damage, Max Ammo, then ATK. Alternatives are splitting 4 Elemental Advantage lines with a mix of Max Ammo and Charge Speed, or a near-end build of 4 Elemental Advantage lines with 1-2 Max Ammo lines and 2 Charge Speed lines. The investment cost is high, so only go for a near-end build when using her without Overload or when you need a middling finished build. Aim for 7.5-8.18% on the two Charge Speed lines, and 2-3 Max Ammo lines are usually recommended.

Energizing Carrot (S1) and Wonderland2 (Burst) at 10 are key. Healthy Carrot1 (S2) at 4 is enough to meet the pierce and healing conditions, and 7 is optional extra investment.

Used as a main DPS in campaign, Tower, and story. Against newer bosses where pierce and cores are blocked, her Raid power drops. In Arena she is used as single-target damage but gets stopped by area defense and invincibility effects.

At 80% HP or more, Pierce lets her shoot through parts and terrain for big firepower.
Her Burst concentrates Charge Speed and ATK self-buffs, so her single-target damage is high.
She grants allies a Charge buff every Full Burst, fitting Sniper Rifle and Rocket Launcher allies.

Newer bosses are weak to pierce and cores less often, so her role as a main Raid and boss pick is narrower than before.
Without Charge Speed and Max Ammo Overload and level 10 skills, her power drops sharply.
Below 80% HP, her Pierce turns off.