FIrefly wants to be in her Ultimate as soon as possible. However, before using it, players will also want to have her teammates buffs ready, such as Harmony Trailblazer or Ruan Mei's Ultimate.
Firefly should only use her Skill during the fight.
Firefly's Ultimate will Advance Forward her by 100%.
Firefly's Ultimate is a countdown similar to Robin. Unlike Jingliu, Firefly can freely play as many turns as she wants before the countdown's turn.
Build Notes
360% Break Effect is what players should get in fight, which is fairly easy thanks to Harmony Trailblazer's buff, Ruan Mei's one and Firefly's Trace that increases her Break Effect according to her ATK higher than 1,800.
Team Notes
Her best general team would be Ruan Mei + Harmony Trailblazer + Gallagher, playing around Super Break.