Mana

A Wind Attacker Nikke who grants allies Attack Damage and ATK buffs at Burst 3 and can even give Charge time reduction to an ally with a long base Charge time.
Metal γ1 provides periodic healing and an auto-revive when an ally is incapacitated, but triggering it removes Metal γ1.

Metal γ1 grants her Increased ATK at the start of battle and triggers only once per battle. Every 10 normal attacks, while she is in Metal γ1, she gives all allies healing proportional to the caster's final max HP. When an ally is incapacitated while she is in Metal γ1, she revives the incapacitated ally (other than herself) with the highest final ATK at a ratio of their HP, and once an ally is incapacitated, she receives Metal γ1 Removal. The revive and Metal γ1 removal are handled automatically during battle when conditions are met, with no step to pick a revive target.

At the start of battle, Metal σ2 continuously increases how fast she fills Burst Gauge. When Full Burst Time starts, if she is in Metal σ2, she gains an Attack Damage increase and Increased ATK for 10 seconds and Metal σ2 is removed. At the same time, she grants Charge time reduction for 10 seconds to the one ally with the longest base Charge time. If she used her Burst Skill right before Full Burst Time ended, Metal σ2's increased Burst Gauge filling speed applies to her continuously again.

Fatal Error!B grants her a sustained damage increase for 10 seconds and deals sustained damage proportional to final ATK to the one enemy nearest the crosshair every 1 second for 10 seconds.

Auto play is enough.
Metal γ1's revive triggers automatically when an ally is incapacitated and the conditions are met, and triggering it removes Metal γ1.

Support Reload Speed with the Resilience Cube and ammo refill with the Bastion Cube. For Charge-focused lineups, the Adjutant Cube for Charge Speed is the runner-up. If Harmony Cube levels differ a lot, use the higher-level cube ahead of the ranking.

Adjust leftover lines, such as Hit Rate, to fit your weapon's magazine pattern.

Metal σ2 holds the Full Burst buff and Charge support, so raise S2 first. The Burst has large sustained damage scaling, so bring it up next. Metal γ1 holds the ATK buff and the healing/revive conditions, so fill it last.

Slot her in Campaign, bosses, and Tribe Tower when you want buffs, Charge support, and sustained damage together.

At the start of Full Burst she grants herself Attack Damage and Increased ATK.
She can grant Charge time reduction to an ally with a long base Charge time.
Her Burst Skill can stack single-target sustained damage with her own sustained damage increase.

Applying a revive removes Metal γ1, and its ATK buff disappears.
The Charge time reduction target is determined by skill conditions, so efficiency varies by lineup.