Honkai: Star Rail Best Firefly Build

Commencing Scorched Earth Operations.

Firefly in her official trailer in Honkai: Star Rail

With Honkai: Star Rail’s version 2.3 release comes the much anticipated Firefly as the newest character. Firefly’s extreme popularity means you’re probably going to get her as well, so here’s how you can build her up to be as strong as possible.

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Strongest Firefly Build in Honkai: Star Rail

Firefly is a Fire Destruction character whose main role in a party is to deal massive amounts of damage. As a Destruction character, she excels in Blast-heavy scenarios (fights with three or fewer enemies), but she is very capable of dealing with everything the game has to offer… with a big catch. More on that later.

Firefly is a Hypercarry, meaning she is best served by her team rather than having others try to DPS alongside her. This is because she is entirely focused on dealing Break Damage, and this aspect is both a massive pro and con at the same time in practically all aspects of her gameplay.

This is no exaggeration, as Firefly deals almost no damage when an enemy isn’t broken. All of her initial contributions to a team before a break comes from her immense amount of Toughness damage. When a Break does occur, Firefly’s damage switches on, and her Hypercarry role comes into effect.

Firefly's Bounty poster in Honkai: Star Rail
Image via Hoyoverse

To ensure Firefly is able to perform her role soundly, she applies Fire Weakness to her foes using her Technique and by activating her Ultimate, which also places her in the Complete Combustion state. This state is where FIrefly will dish out the majority of her damage, but it has a large energy cost to be concerned about. Fortunately, Firefly’s Skill in her normal state provides her with a massive influx of energy every time it is used, meaning that she can use her Ultimate and enter the Complete Combustion state every two turns, on average. Firefly can also perform Super Breaks, which are Breaks with significant damage behind them based on the Break Effect stat.

Despite Firefly being a hypercarry character, she does not use CRIT Rate or CRIT DMG in any regard. These stats are almost entirely useless on her and there is not a practical benefit to stacking either one like you would any other carry. Instead, Firefly wants ATK%, SPD, and Break Effect as her main stats.

  • ATK% – Firefly has a trace that turns ATK% into Break Effect, making it a valuable stat for her.
  • SPD – Firefly wants to be as fast as possible as Hypercarry so that she can get additional turns within combat cycles
  • Break Effect – Her main stat, Firefly wants as much of this stat as she can get, as it scales up her damage via Breaks and Super Breaks.

Focus on these stats effectively means that Firefly is much easier to build than most characters. Now, let’s talk about gearing her up for combat.

Best Relics for Firefly

Firefly's Relics in Honkai: Star Rail
Image by Destructoid

As far as Relic sets go, Firefly really only has one ‘best’ option and that is the new Iron Cavalry Against the Scourge set introduced in the 2.3 update. This set gives her a significant amount of Break Effect, her main stat, but also provides a very healthy amount of Defense Shread for her Breaks and Super Breaks. You can farm this set from the Cavern of Corrosion: Path of Cavalier.

For Firefly’s Planet set, I highly recommend you run the new Forge of the Kalpagni Lantern set as it provides her with additional SPD and gives her an obscene amount of additional Break Effect when attacking enemies with Fire Weakness. Since she can apply Fire Weakness to her foes herself, this is a no-brainer. You can farm this set from the new Divergent Universe added with version 2.3.

Much like Boothill, Firefly craves Break Effect, so try to get as much of as possible on her gear. This includes using Break Effect rope over anything else. Also hunt for SPD and ATK% as well, as both stats provide significant enough improvement to Firefly to be worth the investment.

Best Team Comp for Firefly

Firefly's Team Comp in Honkai: Star Rail
Image by Destructoid

Remember that catch I mentioned earlier? Well, it’s time to talk about it here. Firefly, on her own, is a very weak Hypercarry despite everything I talked about above. She relies, heavily, on teammates that can prop her up to be at her best, and is literally non-functional unless she is run with very specific teammates. Those teammates are Harmony Trailblazer, Ruan Mei, and Gallagher.

Harmony Trailblazer is a requirement for Firefly to be viable, as they provide her with an utterly massive boost to her Super Break damage. This is not an exaggeration: Firefly deals over 50% less damage without Harmony Trailblazer on her team. If you’re planning to run Firefly, you must use this character. It is non-negotiable.

Ruan Mei is also a requirement for Firefly to be functional, for semi-obvious reasons. Ruan Mei’s ability to dramatically boost Toughness Damage means that Firefly can pretty much Break enemies twice as fast. On top of that, Ruan Mei forces broken enemies to stay broken longer, meaning Firefly can dish out more damage. Finally, Ruan Mei’s universal DMG buff also applies to Firefly. Like with Harmony Trailblazer, you should not run Firefly without Ruan Mei.

Gallagher is Firefly’s ideal support in that he helps her Break her targets and provides sustain to the team. Unlike the above-mentioned characters, Gallagher can be substituted for HuoHuo, but he is by far the best option to have on her team.

Firefly’s overdependence on her team is a large detriment as it means she cannot be placed into any other team and be even remotely effective. Trying to run Firefly without Harmony Trailblazer, Ruan Mei, and Gallagher is an exercise in futility and a recipe for disastrous results from her.

Should you pull Firefly’s Lightcone in Honkai: Star Rail?

Firefly signature Lightcone in Honkai: Star Rail
Image by Destructoid

Despite Firefly’s team composition woes, she does not require her Lightcone to be functional. While her Lightcone, Whereabouts Should Dreams Rest, is her best option, On the Fall of an Aeon is an extremely strong alternative that provides Firefly with a large boost in ATK%. ATK% is largely converted into Break Effect for Firefly, which is why it works so well with her. The difference between the two cones is relatively small, so I don’t recommend pulling Firefly’s signature if you have Aeon available for her to use.

Best Eidolons for Firefly in Honkai: Star Rail

Firefly's Eidolons in Honkai: Star Rail
Image by Destructoid

While Firefly is a viable character right out of the box at E0, her E1 and E2 are absurdly strong Eidolons that, if you’re planning to get copies for her, are worth going for if you can. E2 is the best stopping point, but here are all of Firefly’s Eidolons summarized for your reference.

  • In Reddened Chrysalis, I Once Rest (E1) – Firefly’s Skill, while in the Complete Combustion state, ignores 15% of her target’s DEF and the Skill no longer consumes Skill Points. The DEF ignore is strong, but the real value of this Eidolon is the removal of the Skill Point cost. This makes her entire team more functional to play as Firefly becomes far more Skill Point-friendly.
  • From Shattered Sky, I Free Fall (E2) – When using Firefly’s Basic attack or Skill while in the Complete Combustion state to defeat or Break an enemy, Firefly gains an additional turn, which can only be triggered once per turn. This Eidolon is insane, and I’d argue it is more potent than her E6. Firefly will almost always Break her targets, meaning she will almost always get an additional turn, every turn. Insane.
  • Amidst Silenced Stars, I Deep Sleep (E3) – Provides a boost to Firefly’s Skill and Basic Attack damage. It’s fine. Nothing special.
  • Upon Lighted Fyrefly, I Soon Gaze (E4) – Provides Firefly 50% Effect Resistance while she is in her Complete Combustion state. This is her worst Eidolon as it provides nothing to boost her damage.
  • From Undreamt Night, I Thence Shine (E5) – Boosts the damage of her Skill and Talent. Strong overall, but a stepping stone to her final Eidolon.
  • In Finalized Morrow, I Full Bloom (E6) – Effectively, this provides Firefly a Ruan Mei level increase to her Break Efficiency alongside an additional 20% Fire Resistance Penetration. This allows Firefly to drop Ruan Mei for another teammate though I wouldn’t recommend doing so as Ruan Mei’s 50% stacks with this. While this is undoubtedly a strong Eidolon, I don’t think it is worthy of being an E6.
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Darrus Myles
Darrus, a seasoned guide writer and indie developer with nearly a decade under his belt, plunges into the gaming realm like a knight charging into battle (albeit with a trusty keyboard instead of a sword). With RPGs as his domain, he fearlessly slays industry challenges, turning every obstacle into XP for his quest to game domination.
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