Stormblade - Iaido Slash is one of the classes available in Blue Protocol: Star Resonance. They fulfill the DPS role while wielding a Reaper Scythe as their weapon of choice. Find their best build and how to play them properly in our guide. Difficulty:
Stormblade has also access to a second spec - Moonstrike - and if you're looking for a guide to that spec, check here.
Last guide update
07.10.2025
Overview
Best Skills
Talents
Gear
Rotation & How to Play
Spec Overview
Iaido Slash Spec (Iaido for short) is all about Thunder Sigils and burst damage, with all its preferred abilities and talents revolving around them. The Spec also grants access to evolved forms of all Thunder Sigil spending abilities via the talent tree, which you may opt into (but sadly, currently they aren’t optimal to take):
- → Thunder CutIaido Slash
- → DracoflashFlash Strike
- → Phantom SlashRaijin Dash
Specializing in Iaido raises our maximum Thunder Sigil cap, grants us increased bonuses per Sigil spent, and most importantly of all, allows us to constantly spam and chain together Sigil Spenders during our main cooldown -
Pros
- Exceptional burst damage.
- Exceptional endgame scaling.
- High maximum damage potential.
Cons
- High ping and auto unfriendly.
- Low party utility.
- Requires high Crit to function well.
Best Skills
Basic ATK
Skill
Ultimate
Slot 1 - Mandatory
Slot 2 - Mandatory
Slot 3 - Mandatory
Slot 4 - Flex

Thunder Sigil - Thunder Sigils (Sigils for short) are our main resource, which we need in order to use our most powerful abilities, “Spenders”. Spenders can be used as soon as you have at least 1 Sigil, but have their ATK scaler multiplied by 25% per Sigil consumed. Because of this, our abilities are at their strongest when used with maximum Sigils.
Note
Here is how the math of Sigils works on a 150% ATK scaler ability: 150% x (1 + (25% x Sigils Spent)). Sigils do not multiply the flat damage of abilities.

Blade Intent - Blade Intent, Stormblade’s energy bar, is only useful for increasing the attack speed of our spenders through their inherent abilities and talents. You always want Blade Intent, but it’s also generated for free without doing anything in our rotation, so you can ignore it.
Fixed Skills
- - Stormblade’s basic attack is only useful for Iaido during downtime in order to trigger one of the class's core talent effects, Piercing Slash. You’ll be spamming it during downtime for this effect, but nothing more.Judgment Cut
- (Evolved: Thunder Cut) - Our best Sigil spender that makes up a huge amount of our damage, but has a 1-second cooldown. Its cast speed can be significantly sped up by consuming 100 Blade Intent, something we always want to do.Iaido Slash
- The skill can evolve into Thunder Cut, but we don’t use that talent currently.
- - Our Ultimate deals solid AoE damage and generates maximum Sigils on use. It also pulls all eligible enemies in front of you to your position, serving as a grouping tool. Use it to gather enemies or while our Sigil cooldown -Oblivion Combo- is unavailable to fit in extra spenders.Volt Surge
Mandatory Skills
- - Our baseline Sigil generator that generates a measly 1 Sigil on use but has 5 charges. Used to kick start our combo during Volt Surge for maximum Sigils, or after triggering Piercing Slash, which upgrades its generation from 1 to 3 during downtime. Usually not worth using outside of these cases.Overdrive
- - Responsible for our godlike burst damage and the majority of our DPS. Causes all Sigil generation to instead generate the maximum amount for 12 seconds. Also provides Flat ATK, %ATK, and Super Armor. With Talents, during Volt Surge, and with enough Crit Rate, we can spam 6 Sigil spenders back to back continuously.Volt Surge
- (Evolved: Dracoflash) - Our other Sigil spender, which while weaker than Iaido Slash, is crucial to use during our Volt Surge combo to fill in gaps during Iaido Slash’s 1-second cooldown. Also has a 15-second cooldown, but with talents, this can be bypassed almost completely.Flash Strike
- The skill can evolve into Dracoflash, but we don’t use that talent currently.
Flex Skills (Choose 1)
- (Evolved: Phantom Slash) - An optional alternative spender to Flash Strike that deals considerable damage in multi-target situations. Has a huge 25-second cooldown, but this can also be completely bypassed with talents. Not preferred over Iaido Slash or Flash Strike in single target due to lower damage and longer animation time, but can optionally be used in AoE.Raijin Dash
- The skill can evolve into Phantom Slash, but we don’t use that talent currently.
- - Our sole defensive tool. Grants full immunity for roughly 2 seconds on use. If hit during this period, you will counter, with the option to recast for an extra attack that maxes out your Sigil count. Useful when you’re in need of a defensive tool and aren’t using Raijin Dash.True Sight
Skill Priority
>Iaido Slash>>>Flash Strike>Volt Surge=Judgment Cut>Oblivion ComboTrue SightEnsure all abilities you’re using are levelled to 30 - only advancement requires consideration.
Focus on advancing
Talents
Important!
Embedded are two endgame Iaido Slash trees, both with identical pathing - with the exception of 5 talent nodes. One takes Mastery and Armor Penetration, the other takes Crit DMG and a conditional Lightning DMG% increase. Which is better will depend on your gear, Imagines, and whether you’re able to time the Thunder DMG% increase correctly.
You can find a comparison of both choices along with their merits down below.
Gameplay Altering Talents
Most of our talents just help us do what we’re already planning on doing better, but some have a drastic impact on our itemization and rotation. Below is an outline of all the gameplay-altering effects you need to be aware of in the Iaido spec and Base Stormblade talents.
Base Stormblade Tree
- Iai Thunder Dance - Every 3 Sigils generated causes your next Special Attack to deal its damage twice. This talent is double damage for and grants it 2 chances to Crit instead of 1, making our rotation far more consistent. Further incentivizes only using spenders with a high Sigil count.Iaido Slash
- Keen Strike - Grants Basic Attacks a 10/20% chance per hit (scaling with enemies and number of hits) to trigger Piercing Slash, dealing damage and causing our next to generate 3 Sigils instead of 1. A must have for Sigil generation whileOverdriveis on cooldown, consume Piercing Slash during downtime as soon as available.Volt Surge
- will glow purple when enhanced by Piercing Slash.Overdrive

- Swift - Improves our Haste% → ATK SPD% scaling from 1:0.6 → 1:1.6, making Haste a far more valuable stat to build, despite the fact it isn’t one of our “thumbs up” stats.
Iaido Slash Tree
- Flash Frenzy Blade - Upon critically striking with , gains a fixed chance to reset the cooldown ofIaido Slash/ Raijin Dash based on how many Sigils are consumed. Enables the ability to form chains of alternatingFlash Strikees andIaido Slashs, which make up the backbone of our burst combo.Flash Strike
- Zen Moment - Allows us to consume and immediately regain our Blade Intent on Crit, maintaining a constant 100 with enough Crit Rate, improving our attack speed.
- Thunder Sigil Rewind & Flash Sharp Strike - Both these nodes boost Sigil generation, either by refunding after consumption or via critical hits with . When combined withFlash Strike’s ability to convert any Sigil gained into 6, this becomes incredibly potent.Volt Surge
- Dual Blade Intent - Massively accelerates and Raijin Dash animation while at 100 Blade Intent. Also improves the Crit Rate of both abilities and their evolutions by 10%. The speed gain from this talent makes it a must-have.Flash Strike
- Does not cause any of these abilities to consume Blade Intent.
- Duel Awareness - Doubles the chance for Thunder Sigil Rewind to trigger during but halves our Sigil Multiplier from 25% to 12.5%. Hurts our damage ceiling but is what allows us to spam exclusively 6 sigil spenders during our burst window, making our average rotation much more consistent in power.Volt Surge
- Vacuum Slash, Thundrage & Thunder Might - These talents make up the “evolution” playstyle that is currently not considered optimal due to evolved abilities not benefiting from Blade Intent speed bonuses. Without it, these abilities take far longer to cast and cause the playstyle to fall behind a pure -focused build.Iaido Slash
- Wind Assault II (Dungeon & Overworld only) - Is a fantastic pick-up for endgame dungeon-based content, thanks to it dispersing enemies below 15% HP. However, it won’t work on Bosses, so it’s only useful for clearing through trash mobs. Points spent on this talent can be re-allocated elsewhere in pure single-target encounters.
Player Choice Talents
- Arcane and Thunder Reversal - Gain 10% Crit DMG and a conditional 10% Lightning DMG Bonus for 15 seconds. Crit DMG, while nice, is a stat we have a good amount of already thanks to talents, endgame gear, and Muku Chief (our ideal Gold Imagine). Thunder Reversal, however, is challenging to use as it requires you to perform 5 Blade Intent enhanced es before activating, something that usually only occurs at the end of our burst window. While the buff is active, you can’t refresh the bonus or gain stacks for future activations, making uptime duringIaido Slashunreliable at best.Volt Surge
- Advancement and Break Slash - Gain 6% Mastery and a 30% DEF Ignore buff to . This Mastery is equal to 15% finisher damage after conversion on all our spenders, a bonus that is superior to Crit DMG unless you have tremendous amounts of Mastery, as it’s guaranteed and not all our abilities will Crit. Break Slash buffs ourIaido Slashdamage a decent amount, but requires you to critically strike in order to gain the benefits. This talent requires no thought and is mindless to useIaido Slash
Iaido Slash Mastery Variant
Iaido Slash Crit DMG Variant
If you want to create your own Talent tree, check our tool:
Gear
Important!
All gear & talent related info is based on extensive in-game testing, parsing, theory crafting and simulations. If you want to learn more about how damage works to understand our decisions, check out our Damage Formula Guide.
Main Stats
- Crit Rate - Crit is Iaido’s most important stat to stack for the following reasons:
- We possess multiple Crit DMG talents that provide damage only on CRITs.
- Critically striking on certain abilities is required to perform the best rotations, as it regenerates our Blade Intent and also resets Flash Strike’s cooldown. Missing Crits interrupts our burst rotation.
- The goal is for 1 of the 2 hits from Iaido Slash to always Crit to recover our Blade Intent and reset Flash Strike. Build towards 70-80% Crit Rate on Iaido Slash (after including all talents) in endgame to start with. Aim for more than this at higher gear levels.
- Stat goal: 2500+ flat Crit Rate.
- Mastery - Mastery adds an additional multiplier to the Sigil multiplier at a rate of 2.5% Multiplier per 1% Mastery. This multiplier is additive with the Sigil bonus and will always be active in a static amount regardless of how many Sigils are consumed (minimum 1).
Note
Here is how the math works on a 150% ATK scaler ability: 150% x (1 + (25% x Sigils Spent) + Total Mastery Multiplier)
- Haste - Thanks to the Swift talent, we possess incredible Haste scaling; stacking it grants absurd ATK SPD%, accelerating our rotation, allowing for more abilities per Volt Surge.
- Versatility - This stat is always beneficial as it provides an extra multiplicative boost on top of all other DMG increases. Stats suffer diminishing returns, so a small amount of versatility is recommended.
- Luck - Whilst not a completely dead attribute, Luck does not scale with anything major in the Iaido Spec; avoid it if you can.
Bonus Stats
In gear slots you’re not using Set Gear in and which aren’t taken up by your class's signature Class weapon (if you have it), prioritize the following Purple Stats:
Helmet, Armour, Gloves, Boots
Agility%
Weapons & Accessories
ATK SPD% > Melee DMG% = DMG% vs. Bosses = ATK%
Set Gear
Iaido’s 2P and 4P set bonuses are both definitely worth equipping as soon as you’re able to complete Raids and are better than Purple Bonuses. Here is what they do:
2-piece SET
Increases Iaido Slash DMG by 10%.
4-Piece SET
Each Thunder Sigil consumed by Iaido Slash increases your DMG by 1% for 8s.
Class weapon
Our Class weapon is also definitely worth using over purple stats. Instead of a purple stat it grants:
- 15% CRIT DMG.
- Increased stats.
Here are the best modules for Stormblade - Iaido Slash - listed in priority order:
- - Iaido Slash, a Special Attack, makes up a massive share of our damage, meaning a Special Attack Elemental DMG% increase is one of the best gains we can hope for.Special Attack
- - Always a good module for DPS, thanks to its almost always relevant Boss/Elite DMG%.Elite Strike
- - Slightly weaker than Elite Strike, but it works everywhere, giving it an edge in flexibility.Agility Boost
- - Falls behind our top three options, but still a reasonable choice if it’s all you can assemble, thanks to its ATK SPD% increase.Attack SPD
- - CRIT DMG is a powerful stat, but having one portion of this module's stats be defensive holds it back. Roughly as strong as the Attack Speed module.Crit Focus
Important!
Some imagines will not be available to farm until all zones are unlocked - the most vital of these is
.Muku Scout
Premium
F2P
Top Gold Imagines
- - Muku Chief provides passive +%CRIT DMG alongside a powerful active ability that grants even more +%CRIT DMG as well as +Flat Crit Rate. Furthermore, it has two charges, allowing superior uptime compared to other Imagines. Chief not only boosts our damage but also boosts the consistency of our combo as well.Muku Chief
- - Phantom Arachnocrab grants passive +Flat Mastery and additional +%Mastery on use. Mastery boosts the damage of our finishers, which we’ll be spamming constantly during Volt Surge, making the crab a great choice.Phantom Arachnocrab
- - Haste is a powerful stat for this Spec, as we want to fit in as many abilities as possible during Volt Surge and Imagine buff uptime. The combination of massive passive +Flat Haste in addition to a +%Haste bonus on use assists with this goal greatly.Celestial Flier
Top Purple Imagines
- - Muku Scout 5 grants us a passive 15% ATK, provided we are consistently hitting attacks. Upon activation, it doubles the stacks, giving a tremendous 30% ATK buff, amplifying the entirety of our damage. A generic, accessible, and exceptionally strong option.Muku Scout [A5]
- - Brigand Scout Leader grants 10% Agility passively and a further 20% temporarily on use, which together form a tremendous damage increase. While powerful for Agility classes, it is specific to exactly that attribute, making it a less flexible investment than more generic options.Brigand Scout Leader [A5]
- - Boarrier Tyrant is a Special Attack-centric Imagine, making it a great choice for amplifying our Iaido Slash damage. On top of this, you can receive a few copies of this Imagine’s Will for free through the new player rewards. Not as strong as Imagines above, but still solid.Boarrier Tyrant [A5]
- - Muku Vanguard is the generic Thunder DMG% Imagine, granting 7.5% passive Thunder DMG% and a further 16% on use. While solid, it does not compete with higher multiplier options like Boarrier Tyrant, Muku Scout, or Brigand Scout Leader, and is also limited to use on Thunder classes.Muku Vanguard [A5]
Culinary
- Painfly - Grants Elite/Boss DMG% as well as a strong amount of ATK, making it the superior choice.
- Meatfish Skewer - More ATK than Painfly, but without the Elite/Boss DMG% is less powerful.
Alchemy
- Lightning Serum - The best and only choice for our Alchemy consumable when aiming for maximum damage.
- Ruby - Agility (Crit) - The best choice to ensure smooth comboing.
Rotation & How to Play
Burst Rotation
Our goal with our burst rotation is to execute as many 6 Sigil finishers as possible. Open fights with this combo and execute it as frequently as you can throughout battle.
Start your burst rotation by using any available Imagines, then activate
- if not at maximum Sigils.Overdrive
- Use Iaido Slash
- Use when Iaido Slash is on cooldown.Flash Strike
- Wait for Iaido Slash cooldown when missing Crit.
When performing your alternating combo of
Tip
If you accumulate 6 Sigils before using
you can skip out on having to use the first Overdrive.Volt Surge

Downtime Rotation
While waiting for Volt Surge’s cooldown, fill the spare time with your Downtime Rotation. Our Downtime rotation deals substantially less damage but still generates a respectable amount of Sigils for us to spend on less powerful Iaido Slashes.
Follow up your Burst Combo by dumping any remaining Sigils you have into
- Use until Piercing Slash activates.Judgment Cut
- Overdrive to consume Piercing Slash Buff.
- Spend Sigils on Iaido Slash
Continue this priority order until

Can Iaido Slash be played on auto?
Iaido Slash cannot be played on full-auto or semi-auto; it must be played fully manually.