Rosanna: Chic Ocean

Wind

Assault Rifle

Supporter

Burst 2

Tetra

Ferita

■ Activates when entering battle. Affects all allies.
Damage to Parts ▲ 24.26% for 15 sec.
■ Activates when an ally or self destroys an enemy's part. Affects all allies.
ATK ▲ 3% of caster's ATK, stacks up to 5 time(s) and lasts for 30 sec.

Spina di Rosa (Cooldown: 30s)

■ Affects all allies.
Damage to Parts ▲ 24.26% for 15 sec.
■ Affects the enemy nearest to the crosshair.
Deals 70.4% of final ATK as sustained damage every Sec for 15 sec.

Onda Grande

20 sec Cooldown

■ Affects all allies.
Sustained Damage ▲ 20.32% for 10 sec.
■ Affects all enemies.
Damage Taken ▲ 32.23% for 10 sec.

Damage Boost

■ Activates when attacking a radial enemy. Affects this unit's squad only during battle.
Squad ATK ▲ 30% continuously.

Skill recommendations

Skill 1

Skill 2

Burst

7-10

Build

Cube: Resilience, Bastion and Quantum work depending on your team composition.

OL Gear: Low priority to overload. Doesn’t really matter what she gets. Max ammo is a nice addition, but not necessary.

Pros & Cons

Amazing burst with damage taken debuff on all enemies for 10 seconds and sustained damage buff for everyone in the team
Requires low investment to be usable. You can ignore skill 1 & 2 for most content and even for raids you can keep them at level 4

Outside of her burst, her kit is too situational to be worth using. Damage to parts is not bad, but buffs focused on damage are better in most situations if not all
Skill 1 ATK buff is based on her own attack as a supporter unit and the % itself is not enough to be worth investing
Skill 2 extra damage is worthless in most situations unless you fully invest into her, since she is a supporter with low priority to OL