Sō'unga, from the anime Inuyasha, is one of the Three Supreme Swords of the World. Though referred to as a sword, like Tenseiga and Tessaiga, it actually resembles a long blade. Its sheath and hilt are pure white, making it appear even more striking compared to the purple-hued Tenseiga.
According to the lore in Inuyasha, Sō'unga is a terrifying demon sword. Unlike Tessaiga and Tenseiga, it is possessed by an ancient evil spirit. Once wielded by Inuyasha's father—who earned his reputation as a legendary swordsman—Sō'unga's cursed power could plunge the sky into darkness, rot the earth, and drive people to die in despair. The wielder of Sō'unga would destroy everything in existence except themselves, and this devastation would repeat for decades or even centuries. Only demons of immense power could hope to control it.
Tessaiga, Tenseiga, and Sō'unga are collectively known as the Three Swords that Rule the World. Each represents one realm: Tenseiga, aligned with "Heaven," can save a hundred lives with one swing. Sō'unga, tied to "Earth," can open the gates of the underworld and summon back a hundred spirits. Tessaiga, the "Human" guardian sword, can slay a hundred enemies in a single strike.
In battle, Sō'unga surpasses Tessaiga in raw destructive power. In the original story, it took both Tenseiga and Tessaiga together to defeat Sō'unga.
...
During this time, the allied forces gradually regained their composure—especially Tatsumi. Although the Ice Phoenix's aura had rattled him earlier due to his dual use of Teigu, he had since recovered once the beast had left. Now, Tatsumi was leading the charge at the front of the allied forces.
"Hmph. You really think you matter? Die—every last one of you."
Haruki's voice was calm and low.
Then, without holding back, Haruki let his demonic aura flow freely. In an instant, a violent wind swept through the battlefield, and the air turned oppressively heavy. Some of the ordinary soldiers collapsed mid-run, convulsing on the ground, clearly beyond saving. The rest weren't doing much better. Just managing to remain upright was already a struggle. Many of the ten elite soldiers began slowly backing away. Even Tatsumi, under the sheer pressure of Haruki's aura, found his speed dropping sharply.
Because of his connection to the Teigu, Tatsumi was even more sensitive to demonic energy than the others—and the effect on him was far greater.
And this was Haruki holding back. If he had actively used his aura to attack, many would have dropped dead before he even lifted a finger. Even so, the allied forces were now almost entirely incapable of fighting.
Of course, Haruki hadn't released his demonic aura to weaken their morale. That was trivial to him.
Thick, dark red demonic energy began gathering around Sō'unga in Haruki's hand. In just a few seconds, the blade, once gleaming white, turned a vivid crimson. Compared to before, it now radiated overwhelming menace.
Still, Haruki didn't stop. His demonic energy surged without end. As he poured more into the blade, a faint purple-red glow began to shimmer from Sō'unga's edge. The air around it crackled with pressure, and tiny fractures shimmered in space itself.
Haruki continued to compress his demonic power into Sō'unga. The sword hadn't even released its power yet, but the very space around it was already straining to contain it. Yet Sō'unga remained perfectly intact—truly worthy of its fearsome title as the Domineering Sword.
"Prison Dragon Break!"
Once his demonic energy was compressed to a sufficient level—though he could have gone further—Haruki let out a thunderous shout. He raised his hand and swung it toward Tatsumi and the nearly 200,000 allied soldiers assembled before him.
In truth, the allied forces were incredibly unfortunate. Just before Haruki arrived, they had all neatly gathered on a wide-open area within the Royal Palace grounds, waiting for inspection. This convenient formation made Haruki's job easier. Since they were all in one place, there was no need to pick them off one by one—a single massive strike would do.
"Roar!"
A dragon's cry rang out, so loud it felt like it could burst the eardrums of everyone present. Under the stunned gaze of the allied troops, a crimson tornado erupted, spanning nearly half the palace grounds. It instantly swallowed up everyone—Tatsumi, the top commanders, and the entire 200,000-strong force.
But that wasn't the most terrifying part.
Within the tornado, a vividly lifelike blood dragon twisted and surged. Every scale gleamed with terrifying clarity, and its massive form blotted out the sky as it coiled through the storm. Everywhere it passed, it reaped countless lives.
This was no natural phenomenon. The tornado was made entirely from Haruki's demonic energy—its destructive power far exceeded anything nature could produce. Even high-level demons would struggle to withstand this move, let alone ordinary humans made of flesh and blood.
As the whirlwind of demonic energy spun violently, bodies continued to fall. Blood soaked into the storm, deepening its already crimson hue. The air was thick with the stench of blood, and droplets danced like mist in the wind.
The storm raged for quite some time before slowly fading, revealing the aftermath.
What remained was a blood-red wasteland. Severed limbs lay scattered across the ground, along with entrails and shattered remains of buildings. Not a single complete body was left in sight.
With just one attack, two hundred thousand lives were wiped out.
Naturally, Tatsumi was no exception. Even with the formidable defense of the Teigu Demon Armor [Incursio], he didn't last a second. The armor shattered, and Tatsumi was torn apart along with it.
...
"Ah..."
Seeing the devastation from Haruki's technique, the women of Night Raid—who had been lifted into the sky earlier by the Ice Phoenix—were frozen in shock. Just moments ago, some of them had considered resisting him. Now, cold sweat ran down their backs. No one wanted to end up like the soldiers below—obliterated with not even a body left behind.
Even Haruki's own companions were stunned. They had known he could crush the coalition forces, but they hadn't expected it to be this quick or effortless. This was the first time they had witnessed Haruki unleash such overwhelming power.
"I didn't think Haruki was this strong... Looks like I've got a lot of work to do."
Esdeath muttered softly, her eyes gleaming with renewed fighting spirit.