| Type | Icon | Name | SP | Required | Description |
|---|---|---|---|---|---|
| A | 
|
Flashing Blade 1 | 60 | — | If unit's Spd ≥ foe's Spd+5, grants Special cooldown charge +1 per unit's attack. (Only highest value applied. Does not stack.) |
|
Flashing Blade 2 | 120 | Flashing Blade 1 | If unit's Spd ≥ foe's Spd+3, grants Special cooldown charge +1 per unit's attack. (Only highest value applied. Does not stack.) | |
|
Flashing Blade 3 | 240 | Flashing Blade 2 | If unit's Spd > foe's Spd, grants Special cooldown charge +1 per unit's attack. (Only highest value applied. Does not stack.) | |
|
Flashing Blade 4 | 300 | Flashing Blade 3 | If unit's Spd > foe's Spd, grants Special cooldown charge +1 and deals +5 damage per unit's attack. (Only highest value applied. Does not stack.) | |
Cannot use:   
| |||||
Available as a Sacred Seal.
Effects[ | ]
| Effects | Targets | Conditions |
|---|---|---|
 Flashing Blade 3 | ||
| Combat effects | ||
 Special cooldown charge +1per  Unit's attack | Unit | Unit's Spd > Foe's Spd |
 Flashing Blade 4 | ||
| Combat effects | ||
| Special cooldown charge +1 per Unit's attack | Unit | Unit's Spd > Foe's Spd |
 Boosts damage by 5 | ||
Notes[ | ]
- Only attacks performed by the user have the "Special cooldown charge +X" effect. This is true regardless of who initiated combat.
- The "Special cooldown charge +X" effect will stack with the "Special cooldown charge -X" effect.
- For example, if a unit is affected by both
Guard and Special Cooldown Charge +1, the effects will stack and the cooldown will go down without penalty or bonus. - The effects will only stack when the user attacks and the cooldown will go down without penalty or bonus.
- The "Special cooldown charge -X" effect will only take place when the foe attacks.
- For example, if a unit is affected by both
- If used alongside another source of "Special cooldown charge +X", only the higher of the two charge increases will apply.
- This means that if a unit has two "Special cooldown charge +1" effects from two different sources, the battle will play out as if only one "Special cooldown charge +1" effect is active.
- Skills such as Spd/Def Tempo 4 and Spendy Scimitar will neutralize effects that grant "Special cooldown charge +X" to the foe.
- The damage boosting effect is a flat +5 damage that ignores the foe's Def or Res when calculating the damage boost, and can be reduced by damage reduction effects such as Gust, Atk/Spd Excel, and Dodge.
- A foe equipped with
Embla's Ward, 
Múspellflame, 
Niðavellir Axiom, or Gold Perfection will neutralize all sources of damage during combat except the minimum 1 damage from Umbra Burst weapons. - For more information, see Damage calculation.
- A foe equipped with
List of owners[ | ]
| Unit | Skill chain | |||
|---|---|---|---|---|
 | Flashing Blade 1 5  | Flashing Blade 2 5 | Flashing Blade 3 5 | Flash Sparrow 5 |
 | Flashing Blade 1 5 | Flashing Blade 2 5 | Flashing Blade 3 5 | Flashing Blade 4 5 |
 | Flashing Blade 1 5 | Flashing Blade 2 5 | Flashing Blade 3 5 | Flashing Blade 4 5 |
 | Flashing Blade 1 5 | Flashing Blade 2 5 | Flashing Blade 3 5 | – |
 | Flashing Blade 1 5 | Flashing Blade 2 5 | Flashing Blade 3 5 | Flashing Blade 4 5 |
 | Flashing Blade 1 5 | Flashing Blade 2 5 | Flashing Blade 3 5 | Flashing Blade 4 5 |
 | Flashing Blade 1 4  | Flashing Blade 2 4 | Flashing Blade 3 5 | – |
* Alfonse: Prince of Askr, Sharena: Princess of Askr, Anna: Commander, and Forma units cannot be used for skill inheritance or turned into combat manuals.
** Rearmed and Attuned Heroes cannot be used for normal skill inheritance or turned into combat manuals after using their Arcane/Elite Inheritance unless their Arcane/Elite Inheritance is restored via merges.
Alfonse: Prince of Askr, 
Sharena: Princess of Askr, 
Anna: Commander, and 
Forma units cannot be used for skill inheritance or turned into combat manuals.**
Rearmed and 
Attuned Heroes cannot be used for normal skill inheritance or turned into combat manuals after using their Arcane/Elite Inheritance unless their Arcane/Elite Inheritance is restored via merges.Availability[ | ]
Summoning events
| Start | End | Event | Skill |
|---|---|---|---|
| 2017-11-15 | 2017-12-04 | New Heroes: Farfetched Heroes | Flashing Blade 3 |
| 2018-02-28 | 2018-03-05 | Legendary Heroes - Ephraim | Flashing Blade 3 |
| 2018-04-07 | 2018-04-22 | Focus: Cooldown Bonuses | Flashing Blade 3 |
| 2018-07-06 | 2018-07-17 | Focus: Heroes with Luna | Flashing Blade 3 |
| 2018-10-11 | 2018-10-24 | Focus: Tempest Trials | Flashing Blade 3 |
| 2018-11-24 | 2018-12-02 | Focus: Heroes with Vantage | Flashing Blade 3 |
| 2019-02-09 | 2019-02-20 | Focus: Tempest Trials | Flashing Blade 3 |
| 2019-05-10 | 2019-05-30 | New Heroes: Darkness Within | Flashing Blade 4 |
| 2019-06-27 | 2019-07-07 | Focus: Headband Brawl (Block A) | Flashing Blade 3 |
| 2019-08-05 | 2019-08-06 | Focus: Cooldown Bonuses | Flashing Blade 3 |
| 2019-08-10 | 2019-08-11 | Focus: Heroes with Luna | Flashing Blade 3 |
| 2019-08-20 | 2019-08-21 | Focus: Heroes with Vantage | Flashing Blade 3 |
| 2019-08-25 | 2019-09-01 | Focus: Weekly Revival 12 | Flashing Blade 3 |
| 2019-09-30 | 2019-10-08 | Mythic Heroes - Thrasir | Flashing Blade 4 |
| 2019-10-22 | 2019-10-30 | Focus: Heroes with Null Skills | Flashing Blade 4 |
| 2019-12-09 | 2019-12-21 | Focus: New Power | Flashing Blade 3 |
| 2019-12-25 | 2020-01-06 | Legendary Heroes - Celica | Flashing Blade 4 |
| 2020-01-12 | 2020-01-19 | Focus: Weekly Revival 12 | Flashing Blade 3 |
| 2020-03-31 | 2020-04-10 | Mythic Hero - Bramimond | Flashing Blade 4 |
| 2020-05-31 | 2020-06-07 | Focus: Weekly Revival 12 | Flashing Blade 3 |
| 2020-06-14 | 2020-06-15 | Focus: Heroes with Null Skills | Flashing Blade 4 |
| 2020-06-16 | 2020-06-29 | Focus: Tempest Trials | Flashing Blade 3 |
| 2020-07-30 | 2020-08-06 | Mythic Heroes - Hel | Flashing Blade 4 |
| 2020-10-30 | 2020-11-06 | Legendary Heroes - Dimitri | Flashing Blade 4 |
| 2020-11-06 | 2020-12-06 | In the Moment | Flashing Blade 4 |
| 2020-12-28 | 2021-01-05 | Focus: Heroes with Luna | Flashing Blade 4 |
| 2021-01-03 | 2021-01-10 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2021-01-28 | 2021-02-05 | Mythic Heroes - Seiros | Flashing Blade 4 |
| 2021-02-02 | 2021-03-01 | Special Hero Summon (Year 4) | Flashing Blade 4 |
| 2021-03-19 | 2021-03-25 | Focus: Heroes with Null Skills | Flashing Blade 4 |
| 2021-04-28 | 2021-05-07 | Legendary Heroes - Sigurd | Flashing Blade 4 |
| 2021-06-15 | 2021-06-29 | Focus: Double Special Heroes | Flashing Blade 4 |
| 2021-06-20 | 2021-06-21 | Focus: Heroes with Luna | Flashing Blade 4 |
| 2021-07-16 | 2021-07-23 | Focus: Heroes with Null Skills | Flashing Blade 4 |
| 2021-08-15 | 2021-08-22 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2021-08-31 | 2021-09-07 | Legendary Heroes - Micaiah | Flashing Blade 4 |
| 2021-11-19 | 2021-12-03 | In the Moment | Flashing Blade 4 |
| 2022-03-31 | 2022-04-14 | Legendary Heroes - Nanna | Flashing Blade 4 |
| 2022-04-07 | 2022-05-07 | Unlikely Friends | Flashing Blade 4 |
| 2022-05-22 | 2022-05-29 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2022-06-19 | 2022-06-26 | Focus: Weekly Revival 51 | Flashing Blade 4 |
| 2022-07-09 | 2022-07-18 | Focus: New Power | Flashing Blade 4 |
| 2022-08-04 | 2022-08-05 | Focus: Heroes with Null Skills | Flashing Blade 4 |
| 2022-08-13 | 2022-08-27 | Legendary & Mythic Hero Remix | Flashing Blade 4 |
| 2022-10-16 | 2022-10-23 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2022-11-16 | 2022-11-26 | In the Moment | Flashing Blade 4 |
| 2022-11-21 | 2022-12-05 | Focus: Double Special Heroes | Flashing Blade 4 |
| 2023-02-02 | 2023-03-02 | Special Hero Summon | Flashing Blade 4 |
| 2023-02-11 | 2023-02-25 | Legendary & Mythic Hero Remix 1 | Flashing Blade 4 |
| 2023-02-19 | 2023-02-26 | Focus: Weekly Revival 51 | Flashing Blade 4 |
| 2023-04-26 | 2023-05-09 | Unlikely Friends | Flashing Blade 4 |
| 2023-05-28 | 2023-06-04 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2023-07-13 | 2023-07-27 | Legendary & Mythic Hero Remix 2 | Flashing Blade 4 |
| 2023-07-18 | 2023-08-08 | Rearmed Eitr & Rearmed Alcryst | Flashing Blade 3 |
| 2023-10-31 | 2023-11-14 | Mythic Heroes - Veyle | Flashing Blade 3 |
| 2023-11-13 | 2023-12-06 | Legendary & Mythic Hero Remix 2 | Flashing Blade 4 |
| 2023-11-27 | 2023-12-07 | In the Moment | Flashing Blade 4 |
| 2023-12-10 | 2023-12-17 | Focus: Weekly Revival 51 | Flashing Blade 4 |
| 2024-01-14 | 2024-01-28 | Legendary & Mythic Hero Remix 1 | Flashing Blade 3 |
| 2024-03-11 | 2024-03-25 | Legendary & Mythic Hero Remix 1 | Flashing Blade 4 |
| 2024-03-28 | 2024-04-06 | Focus: Lapis & Citrinne's Battle | Flashing Blade 3 |
| 2024-04-01 | 2024-04-09 | Revival: Rearmed Eitr & Alcryst | Flashing Blade 3 |
| 2024-04-13 | 2024-04-23 | Unlikely Friends | Flashing Blade 4 |
| 2024-05-19 | 2024-05-30 | Focus: Tempest Trials | Flashing Blade 3 |
| 2024-06-16 | 2024-06-23 | Focus: Weekly Revival 23 | Flashing Blade 3 |
| 2024-06-17 | 2024-06-21 | Revival: Rearmed Eitr & Alcryst | Flashing Blade 3 |
| 2024-06-30 | 2024-07-07 | Focus: Weekly Revival 51 | Flashing Blade 4 |
| 2024-07-20 | 2024-08-03 | Ascendant, Rearmed & Attuned | Flashing Blade 3 |
| 2024-09-09 | 2024-10-04 | Legendary & Mythic Hero Remix 2 | Flashing Blade 4 |
Distributed units
- Tempest Trials+: A Promise of Joy (×1)
- Tempest Trials+: A Promise of Joy (×1)
- Use Heroic Grails (×20)
- Resplendent Hero (×1)
Combat Manuals
| Start | End | Hero | Currency |
|---|---|---|---|
| 2021-03-04T03:00:00Z | Mareeta: The Blade's Pawn | Divine Code: Part 2 | |
| 2022-11-07T09:00:00Z | 2022-12-28T06:59:59Z | Navarre: Scarlet Ninja | Divine Code: Ephemera 11 |
| 2023-03-06T03:00:00Z | Mia: Budding Blade | Divine Code: Part 4 |
Seal acquired from[ | ]
Tempest Trials reward[ | ]
- Tempest Trials+: Sweet Dreams ( – ): 20,000 Score.
Sacred Seal Forge[ | ]
- Flashing Blade 1: Create for 20 Great Azure Badge, 100 Azure Badge, 40 Sacred Coin.
- Flashing Blade 2: Enhance for 60 Great Azure Badge, 200 Azure Badge, 50 Sacred Coin.
- Flashing Blade 3: Enhance for 400 Great Azure Badge, 1000 Azure Badge, 100 Sacred Coin.
In other languages[ | ]
| Language | Name |
|---|---|
| Japanese | 柔剣 |
| German | Blitzklinge |
| Spanish (Europe) | Hoja rauda |
| Spanish (Latin America) | Hoja rauda |
| French | Lame véloce |
| Italian | Lama fulminea |
| Traditional Chinese (Taiwan) | 柔劍 |
| Portuguese | Lâmina célere |