Blanc
Wind 
Assault Rifle 
Defender 
Burst 2 
Tetra Tier 2 Lucky Guard
■ Activates after landing 120 normal attack(s).
Creates a Shield, equivalent to 11.8% of the caster’s final Max HP, which protects all allies from damage. Lasts for 5 sec.
Rabbit Twins W
■ Activates after Full Burst ends. Affects all allies.
Constantly recovers 3.68% of caster's final Max HP every 1 sec for 5 sec
■ Activates when Full Burst ends with an ally from the same squad on the battlefield. Affects self.
Cooldown of Burst Skill ▼ 40.76 sec.
Showtime
■ Affects all allies.
Constantly recovers 3.84% of caster's final Max HP every 1 sec for 8 sec.
■ Affects 1 ally unit(s) with the lowest HP (except caster).
Gain indomitability for 10 sec.
Max HP ▲ 31.68% for 10 sec.
■ Affects all enemies.
Damage Taken ▲ 39.26% for 10 sec.
Skill recommendations
Build
CUBES
Resilience or Bastion are the best option, like most units in the game. Quantum could be used if your team is low on burst generation.
OL GEAR
Support unit so it doesn’t matter what you get. ATK, max ammunition and elemental damage are desirable but not required.
Solo Raid Usage
This is based on the top 50 players of all NIKKE servers combined. Data is from enikk.app, check their website for a lot more raid data.
Pros & Cons
- Huge damage taken debuff to enemies. One of the best buffs for bossing since characters nowadays get a lot of ATK / Attack damage on their own, making damage taken more valuable
- A lot of utility for the team: heals, shields, debuffs, and provides indomitability on burst
- Useless character if you don't pair her with another 777 member, since she is 60 seconds by default on her burst