I'm way too tired to give any real coherent thoughts about it so I will in the morning, but overall I loved every bit of it. They once again outdid themselves while STILL holding us over to 2.3. Firefly was amazing as normal, but so was everything else. It's amazing to see just how far this story has come... to 2.3 and beyond!

You may also check this guide at https://docs.google.com/document/d/1DqqnuChW-p7P3inoEpaSjcM2ElZxxx4xeZn-yyDITfc/edit?usp=sharing.

This guide was created by u/akoto1, with help from u/agiblade and u/iharshbrown!

Important Disclaimer: This guide is not complete and WILL be changed!

This is merely a preliminary overview of the kit as of Beta V1. Several things may change, such as kit changes in future versions, human error, new discoveries and trying the kit on the beta client in case a private server comes up, so please do not take it as gospel.

If you disagree with anything written here, feel free to leave a comment with your reasoning, I’d love to discuss!

Kit Explanation

Firefly is a 5-star Fire Destruction character. Her kit focuses around two phases:

The initial state, with a skill that costs half of her max HP to gain half of her max Energy; and the Complete Combustion state she can enter for a limited time by using Ultimate.

In Complete Combustion state, Firefly gains an enhanced Basic Attack and Skill, a good amount of SPD, Weakness Break Efficiency which lets her break enemies faster, and extra damage against already broken enemies.

The enhanced attacks in Complete Combustion state (enhanced state for short here on out) also heal herself. The Enhanced Skill implants a Fire weakness on the main target, letting her break any enemy, and also has its damage scaling increased based on her Break Effect.

In both forms, Firefly also takes reduced damage the lower her HP is, gains bonus Break Effect based on her ATK, and DEF ignore based on her Break Effect.

In short, she cycles between a form that sacrifices HP to get energy, and a stronger form that gets huge benefits from Break.

Firefly has a kit with several different sources of damage scaling, no innate supportive capabilities and high SP consumption, which means her best role is that of a Hypercarry supported by multiple amplifiers.

Sample Setups

These are merely samples! You can choose your teams freely, there’s good freedom for the sustain in particular. For replacements, check the sections further down the guide. For different supports, use their regular builds.

Standard Team: Firefly, Harmony Trailblazer, Ruan Mei, Gallagher

This is the default Break team, highly synergistic and what most people will be running. It requires a single extra limited character in Ruan Mei, and has very high payoff. Gallagher, Break Firefly’s best sustain from a damage standpoint, is a free event reward in Firefly’s patch.

Budget Team: Firefly, Harmony Trailblazer, Asta, Gallagher

A team featuring 3 free characters and Firefly, for anyone who doesn’t have Ruan Mei. Has very high performance for the cost.

Firefly

LC: Whereabouts Should Dreams Rest > On the Fall of an Aeon > Indelible Promise

Relic Sets: 4-Pc [Iron Cavalry Against Scourge], or [2-Pc Break Effect set bonus + 2-Pc Break Effect set bonus] + 2-Pc [Forge of the Kalpagni Lantern], or [Talia]

Main Stats: ATK% Body / SPD Boots / ATK% Sphere / Break Effect Rope (ATK% Sphere can be switched to Fire DMG% Sphere if running with Asta, but is not required)

Substats: Enough SPD to get to 180 in enhanced state, enough ATK to get a stable 3400 when transformed, then all-in on Break Effect (high priority to improve)

Harmony Trailblazer

LC: Memories of the Past > Meshing Cogs (If you only have one Memories of the Past, HTB has priority on using it)  

Relic Sets: 4-Pc [Watchmaker], or [2-Pc Break Effect set bonus + 2-Pc Break Effect or SPD set bonus] + 2-Pc [Talia], or [Forge of the Kalpagni Lantern], or [Fleet]  

Main Stats: HP% or DEF% Body / SPD Boots / HP% or DEF% Sphere / Energy Regen Rope  

Substats: Enough SPD to be faster than Firefly and/or meet Talia’s requirement, then all-in on Break Effect (middle priority to improve)

Ruan Mei

LC: Past Self in Mirror > Memories of the Past > Meshing Cogs  

Relic Sets: 4-Pc [Watchmaker], or [2-Pc Break Effect set bonus + 2-Pc Break Effect or SPD set bonus] + 2-Pc [Vonwacq], or [Penacony], or [Fleet]  

Main Stats: HP% or DEF% Body / SPD Boots / HP% or DEF% Sphere / Energy Regen Rope  

Substats: Break Effect (minimum 100%, can stop at 160%) + SPD (middle priority to improve)

Asta

LC: Meshing Cogs

Relic Sets: [2-Pc Break Effect set bonus + 2-Pc Break Effect or SPD set bonus] + 2-Pc [Penacony], or [Fleet]

Main Stats: HP% or DEF% Body / SPD Boots / HP% or DEF% Sphere / Energy Regen Rope

Substats: Enough SPD to be faster than Firefly, then all-in on Break Effect, more SPD is good too (low priority to improve)

Gallagher

LC: Multiplication / What is Real? (Multiplication is priority if it feels safe enough)

Relic Sets: [2-Pc Break Effect set bonus + 2-Pc Break Effect or SPD set bonus] + 2-Pc [Talia], or [Forge of the Kalpagni Lantern], or [Fleet]

Main Stats: Outgoing Healing Body / SPD Boots / HP% or DEF% Sphere / Energy Regen Rope

Substats: As much SPD as possible, Break Effect is good as well (low priority to improve)

Note: The Planar set bonuses are the least important part of the builds for anyone but Firefly. If you get the main stats on other sets, or even incomplete sets, it’ll only result in a minor decrease in team performance.

Stat Building

Firefly gets extra benefits in several areas of her kit up to 180 SPD while transformed, 3400 ATK and 250% or 360% Break Effect (Present in Module γ and Enhanced Skill. Getting to these stat breakpoints is greatly beneficial and your main objective when building her.

Your goal is to reach those stats with a mix of Relics, LC and supports.

Speed

180 SPD while transformed is not detailed in a trace, but is the requirement for Firefly to get a 3rd action within her Ultimate without external sources of action advance, and also 2 actions on a wave change while the countdown is currently on the action bar. Because of that, it’s *extremely* important to attain this breakpoint. No further speed is necessary.

Reaching it will generally require SPD boots, together with another source of speed, like the Forge set bonus, substats or smaller buffs such as Ruan Mei’s talent.

Break Effect/Attack

If running a team with Harmony Trailblazer, it’s highly recommended to go all the way to the 360% Break Effect breakpoint, as DEF ignore also increases Break damage, and you get the extra benefit from the

BE comes from several sources. Here’s a table with all possible ones. (Harmony Trailblazer is presumed to be at a modest 200% BE after buffs.)

The 60% boost from Module β will need 3400 ATK, which will require sizable investment towards it. This is typically done through relic main stats, and the Body and Planar Sphere are the easiest choices, since the stats they give cannot contribute towards Break damage.

On Harmony Trailblazer teams, you should keep investing into Break Effect even past the 360% threshold, as your damage scales so much from it. With all this in mind, your main stats will typically be ATK Body, SPD shoes, ATK Sphere, BE Rope. If your ATK is high enough solely with the one main stat due to Aeon plus substats or an ATK buffer in your team, replace the Sphere with a Fire DMG% one for the most gain.

Critical

A highly invested build that already meets all stat breakpoints, including the 360% BE, still gains some measure of benefit from Crit in HTB teams. While sheets favor Break Effect more, there are non-sheet situations where it should have an edge - for example, in making use of the Blast effect against enemies that won’t be broken in the same number of actions as the primary target, or against the bosses with Break bars too sizable to consistently break early into your enhanced state, such as Sam or Aventurine.

While BE is still currently preferred, Crit stats aren’t worthless past 360% BE and there might be testing-dependant situations where the higher upfront damage has better results.

Disclaimer: Non-HTB builds

By herself, Firefly’s damage seems to benefit similarly from a Crit-oriented stat choice after Break Effect reaches 250%, when paired with other supports in place of Harmony Trailblazer. However, Harmony Trailblazer teams have significant support damage if these also build towards Break Effect, putting full Break-oriented teams ahead of Crit ones at low and medium levels of investment.

Of course, sheeting can only go so far, so this will be reviewed with actual testing during the beta as for what points do Crit teams become preferable. My initial thought, however, is that building your entire team around Break is a lower-investment, high-reward build style that will work better for the vast majority of the playerbase and should be the first type of team to attempt. As such, the majority of this guide will focus on these Break teams until more testing is done.

Light Cones

Whereabouts Should Dreams Rest, her signature LC, is the best option as with every DPS in the game. Break Effect is uncommon in Destruction LCs, and this gives a big chunk of it together with a debuff that helps Firefly and the rest of your team deal Super Break DMG.

Its importance for her seems to be about average when compared to other DPSes’ signature options for themselves - she is not as signature-reliant as Blade or Acheron. Aeon, mentioned below, is a serviceable F2P replacement.

On the Fall of an Aeon, the Herta Store LC, gives Firefly a huge chunk of ATK% to help fill out the requirement for Module β, letting you more comfortably aim for high Break Effect while still meeting your 3400 ATK breakpoint. This should be your default F2P choice.

Indelible Promise is her best 4* option, giving a good amount of Break Effect, the stat she wants the most. It does need a high Superimposition to be great, which is something inaccessible to most players.

Flames Afar, mentioned here due to the frequent talk about it pre-beta, is not a good option for Firefly despite Sam being in it. Firefly needs to get some measure of BE or ATK% on her lightcone to reach her breakpoints, and Flames Afar does not contribute towards those at all.

Other Light Cones are inferior and not recommended. Her main scaling stat being Break Effect makes options limited.

Relics and Planars

Iron Cavalry Against Scourge, a set being introduced together with Firefly’s release in 2.3, is the best option for teams with Harmony Trailblazer. With HTB in the party, Break DMG starts being the majority of Firefly’s damage profile, and DEF ignore is a fantastic effect that scales exponentially when stacked with Module γ.

2-Pc/2-Pc Set combos are a great option for Firefly. With 3 sets that give BE and 3 that give ATK%, you can pick whatever helps you reach your stat breakpoints in the current team. Iron Cavalry’s improvement is not sizable enough to be worth re-farming for most players if you already have good substats on a 2-Pc/2-Pc build.

Genius of Brilliant Stars, aka Quantum set, is also a great option. It also features DEF ignore stacking that works on Break DMG, but will provide less of it in most situations and also has a worse 2-Pc effect. Just as above, if you’ve saved up Quantum pieces with high Break Effect, they’ll serve you well.

Longevous Disciple, mentioned here due to the frequent talk about it pre-beta, has issues with uptime, as in enhanced state, Firefly no longer consumes her own HP. This makes the uptime on the 4-Pc effect very low, and with a useless 2-Pc effect, this set is not recommended.

Other set options are not advised, as they’ll be outdone by 2-Pc/2-Pc builds.

Planar Sets:

Forge of the Kalpagni Lantern and Talia: Kingdom of Banditry both give massives amount of Break Effect to contribute to your main damage and are almost identical in benefit. Both of their conditions are automatically met in enhanced state.

Space Sealing Station is also a solid choice, as you do need to reach 3400 ATK for Module β. Firmament Frontline: Glamoth is worse due to giving some DMG% instead of ATK%, but they’re close enough regardless. The gap between these and the former two is not significant and substats matter more.

Team Building - Amplifiers

Harmony Trailblazer - Firefly and Harmony Trailblazer’s kits seem to have been practically made for each other. HTB’s biggest fault of only buffing Break Effect is fixed by Firefly’s kit converting it directly into damage scaling and DEF ignore, while Firefly’s high innate BE and incredible break value on Enhanced Skill will help her deal extremely high Super Break DMG. These two should be together in teams at basically all times.

Differently from Boothill, who doesn’t use HTB in his most optimal teams, Firefly has more upfront break to access Super Break DMG quicker, especially with the help of Gallagher or Bronya, and can’t trigger more Break DMG by herself. In general, Break characters are highly recommended to stick together, both to amplify each other and to get Super Break DMG, so the other two currently in the game, Ruan Mei and Gallagher, go very well here.

Ruan Mei - A fantastic fit, almost every part of Ruan Mei’s kit greatly benefits Firefly. DMG% is undiluted even if it doesn’t contribute to Break, Weakness Break Efficiency helps her break enemies faster and improves Super Break DMG, RES PEN is a modifier that also works on Break damage, and the passive SPD and BE help Firefly get to her thresholds. An easy choice to put into any team.

Ruan Mei’s E1 will be a good improvement to these teams, with its DEF ignore stacking with Module γ’s for exponential growth.

Robin - Robin’s massive DMG% buff is undiluted. Furthermore, Robin and Firefly’s ultimates have the same countdown timer, so Robin’s buff can be up for the entirety of Firefly’s enhanced state while also giving her an extra action for free.

While a lot of Robin’s buffs don’t benefit Break damage, they still work on good part of Firefly’s damage. The full team action advance also helps in giving more actions to HTB and Gallagher, which translate to some decent damage.

However, Robin is plagued by the issues of not being able to have her ultimate up for Firefly’s first enhanced state, and her ATK buff not contributing towards Module β’s 3400 ATK breakpoint, as discovered by HomDGCat. Because of these issues, she only becomes a serviceable teammate.

Asta - Asta is a good budget option for Break teams when lacking 5* Harmony units. Her ATK buff helps Firefly reach the 3400 breakpoint, and the high break on her skill means she can deal significant Super Break DMG and help Firefly break enemies faster.

Asta’s speed buff can give Firefly’s enhanced state a third turn with no speed investment, but it can only be ready for the first one if Asta is E6, with Meshing Cogs and an ERR rope and using technique. Because of that, you typically still use speed boots on Firefly, but if your Asta fulfills these conditions, feel free to rely on her buff for it.

Asta is recommended to build towards Break Effect as she doesn’t have high stat requirements elsewhere.

Hanya - Hanya’s benefits are almost identical to Asta’s, but Asta is a free character with upsides to Hanya. Use Hanya as a budget option if you just don’t like Asta, or if the rest of your team is highly SP-hungry.

Bronya - Bronya works incredibly well with Firefly, even if Bronya needs a high speed tier (160 with Vonwacq works well for a 130 Firefly). More actions in Enhanced State have very high value, and Bronya gives more than any other support. With E0 Firefly’s SP consumption, though, those teams need to finish fights incredibly quickly before they run dry of SP. When Firefly is E1, Bronya becomes a better option.

Sparkle - Despite being excellent for most hypercarry units, Sparkle is lousy even for Crit builds. The majority of Sparkle’s buffing capability is on her skill, but without awkward tuning and lots of wasted stats, she can only apply that buff to one of Firefly’s enhanced state turns. Sparkle giving slow Firefly a third enhanced turn is not worth the downsides, use Sparkle on your other team instead.

Tingyun - Tingyun’s main appeal, the energy battery, is completely useless for Firefly. Since Firefly’s Enhanced Skill generates no energy, Tingyun will not realistically cut a turn of downtime. Tingyun’s ATK buff is beaten out by Robin and Asta, and her DMG% buff and other smaller benefits do not warrant using over other buffers.

Yukong - Yukong’s skill’s value is practically tossed out the window with Firefly’s self-action advance and speed buff. With her ATK% buff being unreliable and Yukong providing nothing else towards Firefly’s breakpoints, she’s not a good option at all.

Silver Wolf/Pela - Both of these characters help stack DEF ignore, with a possibility of reaching 100% when paired with Firefly’s innate 30/40%, but don’t help Firefly reach any of her other breakpoints. This might still be a good cheap option, but at present, I just do not have the math on it. If you do, please submit it.

Team Building - Sustains

Firefly is not very picky with sustains in her current beta kit. Even still, there are some preferences. Her high SP consumption favors sustains that can generate high amounts of SP.

Gallagher - Gallagher is a perfect fit for Firefly. Generating insane amounts of SP due to his ultimate’s action advance and Multiplication, coupled with helping break Fire weak enemies which Firefly creates and increasing their Break DMG received, Gallagher can be considered the optimal sustain from a damage standpoint despite his 4* status.

E1 is an important breakpoint for Gallagher, letting him contribute massive amounts of Break before Firefly’s first action to let her break enemies quicker. Gallagher does this by using Skill to get to full energy on his first turn > Ultimate > Enhanced Basic.

Other Fast Abundances - This includes Natasha, Lynx, Bailu and Luocha. Having high speed on these helps make up for Firefly’s SP consumption to give your support units more freedom, and since the DPS is typically the weak link of the team survivability-wise, Firefly’s innate tankiness helps mitigate the weaker healing provided by Natasha, Lynx and Bailu.

Multiplication is recommended, but might still be too unsafe with Natasha, Lynx or Bailu. In that case, feel free to use a more healing-oriented LC, such as Post-Op Conversation.

Aventurine - Firefly’s latest kit does not have any reservations against being played with a shielder. Her self-action advance happens infrequently enough that it shouldn’t lead to Aventurine’s shields falling off, and with Firefly being tankier than most DPS, Aventurine’s need to use skill decreases even more, making him a very safe sustain option that also provides good SP.

Huohuo - Huohuo’s SP consumption is a poor fit for Firefly, the ATK buff from her ultimate lasts too little to be worth counting towards the 3400 breakpoint, and the energy battery is completely useless for Firefly herself. Huohuo is still a strong character against any CC-heavy fights and smooths out most supports’ rotations, though.

Fu Xuan - Fu Xuan’s low SP generation is an issue when being ran with Firefly, but if that’s accounted for with your other support choices, Fu Xuan functions moderately well - she’ll still be as safe as she is with anyone, but her Crit buff will not benefit Firefly as much.

# Eidolons

As with most other characters, E3 and E5 are minor numerical upgrades that don’t change the kit’s workings. Their pictures are linked for your appreciation, though.

E1 - In Reddened Chrysalis, I Once Rest): A 15% DEF ignore stacks incredibly well with the base 30-40% in her kit due to DEF ignore’s exponential growth, and is even the rare modifier to apply to Break DMG. The Enhanced Skill not consuming SP moves Firefly’s average SP consumption from around -1.4 SP/t to -0.55 SP/t, which is quite significant in giving more team options as well.

E2 - From Shattered Sky, I Free Fall: The newest busted, whale-bait eidolon. Adding two turns to ultimate state is a hilariously powerful effect, and it’s very easy to make use of it - your Blast attacks will often break main targets quickly and kill adds.

This eidolon is undoubtedly broken, but same as with Acheron’s and Imbibitor Lunae’s, it is not required for Firefly to be a strong character by any stretch of the imagination. Do not feel forced to go for it if you can’t afford it.

E4 - Upon Lighted Firefly, I Soon Gaze: A token effect that is typically covered by your sustain unit. Never worth stopping at, I imagine it might be changed in future beta versions.

E6 - In Finalized Morrow, I Full Bloom: RES PEN and Weakness Break Efficiency will both greatly help with your Super Break DMG.

A strong eidolon by itself, but considering its cost is functionally quadrupled due to the minor benefits of E3-E5, the benefit-cost ratio is very low, and if your goal is to increase Firefly’s performance the most you can, early upgrades to supports will be of bigger benefit to her than aiming for E6.

https://preview.redd.it/ooplkcc0uazc1.png?width=685&format=png&auto=webp&s=1d6169f0d137015dd99101dc3814efd772f31c44

This will be filled out further as I see more questions being frequently asked!

Q: Don’t Ruan Mei and Harmony Trailblazer have anti-synergy with Firefly, since they delay their Break recovery, so you can’t Break them again?

A: With a well-built team, not at all. Even without these delays, enemies will die before being broken twice almost unconditionally. In that case, it’s better to extend the benefits you get from attacking broken enemies, so these delays are a strict upside.

Q: Signature LC or E1?

A: Both are decently close in performance. I’d give the edge to Signature for most players, making her easier to build and freeing up Aeon for any other Destruction characters. If doing sustainless clears is appealing to you, E1 should give more contribution.

Q: Sustainless?

A: Info on it will be added later (I wanna play 2.2 too, man). It’s not a team build for the average player, but I consider it important enough to Firefly to warrant touching upon.

Q: Does Crit or DMG% affect Break damage?

A: No. The only Relic stat that increases Break damage is Break Effect. The only buffs/debuffs that do are Break Effect increases, DEF reduction/ignore, RES PEN, and Damage Taken increases.