The so-called "Black Flash" occurs when the delay between physical impact and cursed energy output is less than 0.000001 seconds, creating a spatial distortion. Its power is calculated by raising the product of physical and cursed energy strengths to the 2.5th power—a "critical hit" wrapped in a burst of light.
For instance, during Gojo Satoru's fight with Ryomen Sukuna, a single Black Flash from Gojo had Sukuna reeling, eyes rolling back in unconsciousness, making one wonder if Sukuna might have been killed right then and there, if not for Mahoraga's timely interference.
However, the Black Flash isn't just about power amplification. Sorcerers who've experienced Black Flash are worlds apart from those who haven't in terms of their closeness to cursed energy's core.
In the five minutes after achieving a Black Flash, sorcerers enter a state akin to the "zone" that athletes describe. Cursed energy flows as naturally as breathing, without the need for forced control.
If one word could capture this feeling, it would be burning.
At this moment, the bluish cursed energy covering Jasmine's body was aflame, as if ignited.
Her physical strength wasn't naturally high—at least not on par with someone like Itadori Yuji, who could leap several floors without enhancing himself. But with cursed energy reinforcement, combined with her grounded, powerful Bajiquan techniques, Jasmine could unleash immense force in an instant.
"Strike with the shoulder and shatter the heavens; stomp the ground to shake the Nine Provinces." That is the essence of Bajiquan.
Bajiquan emphasizes strength rooted in the ground, power rising from the heels, transmitted through the waist, and released through the fingers. It requires a strong foundation and forbids high kicks, limiting leg movements below the knees. But in exchange, the punches are ferocious and swift.
Outwardly, it might seem that the monster struck by Jasmine's punch only had its chest caved in, but internally, it was obliterated—truly dead beyond saving.
And yet…
"It's… not vanishing?"
Jasmine knew that cursed spirits, upon death, reverted to their purest form of cursed energy and dispersed entirely, even more completely than if they'd been reduced to ash.
That's why jujutsu sorcerers typically didn't have to worry about cleaning up corpses after dealing with cursed spirits.
Even jujutsu sorcerers' shikigami, similar in essence to cursed spirits, would dissipate naturally upon death.
If these creatures weren't cursed spirits, could they be some type of physical entities? Jasmine had never heard of living beings with such twisted cursed energy.
Her thoughts and questions only lingered for a brief moment—she remained aware of her current predicament.
"Don't cause Baobhan Sith any trouble." That thought kept her hyper-focused, allowing her body to move with perfected technique.
As the monster charged, Jasmine stomped, cracking the ground, and struck with her right fist, gathered at her side and swirling with cursed energy.
Bang!
In that instant of impact, the struck area of the monster twisted violently, its back erupting in a spray of blood.
At nearly the same moment, that ominous black lightning appeared again, streaking like cracks through the air.
Black Flash. A double hit.
If another sorcerer were watching, they would've been speechless at this sight.
No sorcerer could intentionally trigger Black Flash at will. Even those who had managed to pull it off once rarely managed a consecutive strike.
But Jasmine wasn't bound by convention.
Baobhan Sith, having crossed over from another world, knew much about this world's workings. With Da Vinci's genius guidance and a crafted training plan, Jasmine had access to unparalleled teaching.
Where else could you find such powerful tutelage?
Jasmine's raw talent might not match that of Yuta Okkotsu, Gojo Satoru, or Ryomen Sukuna, but she had the two best teachers in the world, which allowed her to master Reverse Cursed Technique and Black Flash with surprising ease.
Gojo nearly died before he learned Reverse Cursed Technique, after all.
As Jasmine tore through her monstrous foes like a tiger among sheep, Baobhan Sith, too, maintained her effortless dominance.
---
"Come on, come on, give it your all."
On the charred black soil that had long become a dead zone, Baobhan Sith leisurely held Jogo's head with one hand, her left arm tucked behind her, her tone unhurried.
Purple blood dripped from Jogo's body, pooling into a dark purple puddle beneath him.
"Fight with all your strength, use every last trick and ounce of bravery. I don't mind your battle of attrition, your delaying tactics, your traps, or your mind games. Use everything you think counts as 'strength,' because unless you throw everything you have at me, you'll never win."
"Come on now, try harder, get stronger, push yourselves."
"The only reason you're still alive and still holding me here is that I believe you can do better. I believe you can still amuse me. In other words, the moment I decide you're no longer capable of improvement, that this is the best you can manage…"
Baobhan Sith turned her gaze from Jogo's nearly lifeless form to Hanami and Dagon, lying battered on the ground not far away. A flash of murderous intent, as cold as death itself, crossed her eyes.
"That's when I'll kill you without hesitation."
There was no defeating this monster!
None of their attacks could harm her; even when all three of them joined forces, they were simply played with.
Forget victory; Jogo felt like he was dancing on the edge of death with every second they managed to stall her.
Just as she'd said, she could have killed them all in an instant, not giving them the slightest chance to flee.
She'd refrained from killing them only to see how far they could go.
So they had to get stronger—stronger just to survive.
Not to defeat this demon before them, but simply to stay alive.
For Hanami and Dagon's sake, Jogo had to grow stronger!
His tattered arms, little more than ragged flesh, trembled as he raised them.
Though his limbs were ground down to nearly powder, with only an outer layer intact, he still struggled to lift them.
Baobhan Sith waited, watching with interest.
Finally, after what felt like an eternity, Jogo's hands came together, his shattered jaw barely moving as he forced out words.
"D-Domain… Expansion…"
The pinnacle of jujutsu—the Domain. This was Jogo's ultimate move.
Until now, he'd never succeeded in casting it, not even at full strength, let alone in his current state, depleted of cursed energy and on the verge of death.
But…
"Success isn't the point; it has to work!"
Even if this would be the only Domain he could ever cast in his life, even if the cost would be everything he had—even if Jogo himself ceased to exist after today.
"I was the one who chose to challenge this demon, so, at the very least… I have to let Hanami and Dagon…"
For the sake of success, Jogo placed a curse upon himself.
A vow that could only be used once—a curse of death.
This terrible curse became the strongest binding vow upon Jogo, exchanged for equally formidable enhancement.
In one final blaze, as though his life were flashing before his eyes, a massive surge of cursed energy erupted from his broken body, terrifyingly vast, greater than even the combined strength of the Three Calamities at their peak.
And so, the world turned upside down.
The full moon above Baobhan Sith and Jogo was swallowed by darkness, the scorched earth transforming in an instant into the mouth of an erupting volcano.
Domain Expansion—Coffin of the Iron Mountain!