Cocoa

A Fire Code Burst 1 support whose strengths are cover restoration and debuff cleansing, but she loses out to general-purpose Burst 1 picks like Liter.
She is almost never in core Story, Raid, or Arena lineups, and is only used on stages where cover matters or as a Union Raid substitute.

Full Charge shots build Professional Tomato Sauce2 stacks, and Professional Maid LeaderB cleanses allies' debuffs. When Professional Tomato Sauce2 is at max stacks, all enemies' ATK is lowered.

Professional Origami1 restores allies' cover every 15 sec, and cleanses 1 debuff each from 2 random allies that have debuffs. Professional Maid LeaderB's cooldown is 20 sec.

Build Professional Tomato Sauce2 stacks by landing Full Charge shots.
Restore cover with Professional Origami1 before it breaks.
Full Charge and cover timing are better done manually; everything else can be left on Auto.

There are almost no combos tied to recent core Raid or Arena squads. Things like cleansing Privaty's stun are not proven top meta setups.

For cover and healing, use the Vigor Cube and Healing Cube; for keeping Professional Tomato Sauce2 stacks up, use the Adjutant Cube (Charge Speed), in that order.

Skip DPS-oriented Elemental Advantage and ATK lines. Consider Charge Speed for Professional Tomato Sauce2 stacks, and DEF or max HP lines for survival.

If you don't plan to use her, leave her at 1/1/1. When raising her, level Professional Tomato Sauce2 first to meet the condition for the Burst ATK reduction, then reinforce Professional Origami1's healing.

Occasionally used as a substitute Burst 1 in Story stretches where cover breaks often, or in Union Raid, when Liter isn't available. Not suited to core Arena or general boss lineups.

Professional Origami1 restores cover and cleanses debuffs from 2 random allies.
After Professional Tomato Sauce2 reaches max stacks, Professional Maid LeaderB lowers enemy ATK.
Keeping stacks up with Full Charge reduces the damage over time she takes.

As a Sniper Rifle, her Burst Gauge contribution is low.
She has no taunt, so if the team collapses she may be the only one left standing for a long time.
She specializes in cleansing and cover, so she wastes a slot in regular damage lineups.