Folkwang

A Burst 2 Water Defender Assault Rifle and tank support who helps the 2 highest-ATK allies with taunt, shields, and an HP recovery buff.
She is rarely a main pick in story, bosses, or Raids.
She was occasionally used in tough survival content like early Special Interception, but newer defenders and healers have pushed her out.

S1 gives the 2 allies with the highest ATK a shield and increased HP recovery, and S2 taunts the enemy with the highest ATK while raising her own Max HP. Her Burst applies a shield and healing based on damage dealt to 2 allies chosen by the same rule.

Use S2 to taunt the highest-ATK enemy, then raise her own Max HP.
Use her Burst to give the 2 highest-ATK allies a shield and lifesteal healing.
Auto is enough by default.

There is little evidence of her being paired in the same squad in the recent meta.

Use the Vigor Cube to grow the final Max HP behind her shields and healing, and the Endurance Cube for DEF. Use the Resilience Cube to handle Assault Rifle reloads. If Harmony Cube levels differ a lot, use the higher-level cube before the ranking.

Her shield and healing scale with final Max HP, so prioritize DEF lines, and set Elemental Advantage damage and ATK for her own shooting as lower priorities.

Unless she is a meta core unit, save skill books and only raise Starting Whistle, Harder, Better, Faster1, and Sprint2 to 4 when you use her. S2 covers taunt and her own HP, while S1 and her Burst are key for protecting allies. Maxing to 10 gives little return for the investment.

She is rarely seen in top Solo Raid lineups. She is occasionally used for survival in early Special Interception and similar content.

Her S2 taunts the highest-ATK enemy and raises her own Max HP.
Her S1 gives the 2 highest-ATK allies a shield and increased HP recovery.
Her Burst applies a shield and healing based on damage dealt to the same targets.

Her shield and healing contributions are weak compared to newer defenders and healers.
Her S1 cooldown is long, so her shield cycle is sparse.
She is rarely a main pick in the competition for Burst 2 tank and support slots.