Rapunzel: Pure Grace

She is rarely used in the top core tank slot in Raids.
She is fairly easy to obtain through milestones and Spare Bodies, but to keep her ally ATK buff running you have to hold Full Charge for a while with the shared shield up, which takes more effort than top core tank lineups.

At the start of battle and every time she uses her Burst, she gains a lasting shared shield proportional to her final max HP.
If she holds Full Charge for 1 second or more while the shield is up, all allies gain a lasting Attack Damage increase.
Using her Burst briefly grants her a max HP increase and briefly grants all allies an Attack Damage increase.
Full Charge attacks heal her proportional to her final max HP. Holding Full Charge for 1 second or more while the shield is up chips away at her current HP but periodically restores shield HP for the shared shield.

Hold Full Charge for over 1 second before firing to meet the ally Attack Damage increase condition while the shield is up.
Full Charge attacks heal her, and if the shield is still up, the Full Charge hold window restores shield HP.
Leave her on auto by default, and only correct the aim by hand when Charge holding and hits get out of sync.

As a sniper, prioritize the Bastion Cube to ease reload burden, and treat the Resilience Cube as the runner-up for Charge-focused play. If Harmony Cube levels differ a lot, use the higher-level cube ahead of the ranking.

If Full Charge is a large share of her damage, take Charge Speed and Charge Damage, and set the rest with Elemental Advantage damage and ATK. Fit the remaining Overload slots, such as Hit Rate, to engagement range.

Garden of UtopiaB holds both the max HP increase and the ally ATK buff, so raise the Burst first. Sanctuary1 holds the shared shield and the Full Charge-linked ally buff, so raise S1 next. Pray2 holds Full Charge healing and shield upkeep, so bring S2 up after that.

She can go in as a defensive Burst 1 who supports the squad with a shared shield and Burst ATK buff in Campaign, bosses, and Tribe Tower. Build the Full Charge hold condition into your squad plan.

She refreshes the shared shield at the start of battle and on every Burst.
Her Burst grants herself a max HP increase and allies an Attack Damage increase at the same time.
Meeting the Full Charge condition keeps the ally Attack Damage increase going, and Full Charge attacks also bring healing and shield top-ups.

Her lasting ally ATK buff requires holding Full Charge and keeping the shared shield up at the same time.
Holding a sniper Full Charge and landing hits take effort.