VIDEO GUIDE
QUICK ROUTE
Do it in this order
Unlock Black Flash near spawn
Black Flash is not a Cursed Technique or weapon. It is a separate damage mechanic unlocked through its own three-part NPC questline.
Start with the Black Flash One NPC close to spawn. You must be at least level 400 and spend 250,000 Yen to finish the first quest. After paying the cost, Black Flash becomes available to use.
Activate Black Flash on PC or mobile
On PC, hold the left mouse button, then press the right mouse button twice. On mobile, hold the M1 button, then tap the screen twice.
Practice the input before starting the long upgrade quests. A successful activation is what advances those quests; the number of targets hit does not change the amount of progress.
Understand how Black Flash damage scales
Black Flash combines your character's combat stats with damage based on a percentage of the enemy's current health. It is especially effective at the beginning of fights against bosses with billions of health.
Because the health-based portion uses current health rather than maximum health, it becomes smaller as the boss loses health. Do not expect the opening hit and a late-fight hit to show the same number.
Attack, Critical Damage, and Critical Rate are the main stats to prioritize. Stronger clans, Cursed Techniques, gear, emblems, and accessories improve those stats and therefore improve Black Flash damage.
Upgrade Black Flash with 1,000 activations
Find Black Flash Two near the Sorcery Heavenly Restriction Doctor. Its quest requires 1,000 Black Flash activations.
The quest counts activations, not enemies hit. Activating Black Flash once gives one use whether it hits no enemy, one enemy, or a group. Hitting more targets will not complete the quest faster.
After reaching 1,000 uses, return to Black Flash Two and speak to the NPC again to receive the next upgrade.
Farm activations efficiently
The simplest farming method is to stand against a wall and repeatedly activate Black Flash. You do not need to find enemies because an activation counts even when nothing is hit.
For manual farming, use a comfortable rhythm and take breaks during the 10,000-use grind. If you consider automating the input, first confirm that the current Roblox and Jujutsu Zero rules permit it. The guide does not recommend risking an account for faster quest progress.
Finish the 10,000-use final quest
The third quest comes from Black Flash Three, located underneath The Recruiter. This final step requires 10,000 Black Flash activations.
Use the same wall method from the previous quest. When the counter reaches 10,000, return to Black Flash Three and finish the quest to unlock the final Black Flash upgrade.
Best Black Flash build
The recommended core is a fully leveled Amanai clan, an upgraded Shrine Cursed Technique, Sukuna's Mark as the passive, and Cursed King Tattoo as the accessory.
Equip the strongest gear and emblem you currently own. Prioritize Attack, Critical Damage, and Critical Rate rather than copying one exact gear list with weaker rolls. Equipping and upgrading a strong Cursed Technique improves your character stats even though Black Flash itself is not a technique.
- Clan: Amanai, fully leveled.
- Cursed Technique: Shrine, upgraded as far as possible.
- Passive: Sukuna's Mark.
- Accessory: Cursed King Tattoo.
- Gear and emblem: Highest available Attack, Critical Damage, and Critical Rate.
Realistic damage expectations
In the owner-tested build, the first Black Flash hit dealt about 900 million damage, followed by four additional Sukuna's Mark ticks. The combined result was roughly one billion damage against the test dummy from one activation.
That result is an example, not a guaranteed number. Your stats, upgrades, target, and the enemy's current health all change the outcome. Against raid bosses with extremely high current health, a completed build can reach billions of damage, but the health-based bonus falls as the fight continues.
Common mistakes
- Do not farm groups of enemies expecting each target to count as another quest use.
- Do not judge the build from a nearly defeated boss; the current-health bonus is already smaller.
- Do not leave Amanai unlevelled when testing the recommended setup.
- Do not ignore Critical Rate while stacking only Attack and Critical Damage.
- Do not treat the one-billion dummy result as a guaranteed number for every player or every raid.
- Do not use prohibited automation for the activation grind.
