Ultimate Suffering (Patreon)

AN: This is a commission from Jesus, who wanted a Naruto/Konosuba fusion. You can google translate Sasuke's new clan's name if you want a spoiler.

ooOoo​

Ultimate Suffering​

Sasuke Kouma had grown up in the shadow of his clan. They had been one of the two clans that helped found Konoha, after all. When he was young, nobody ever had much to say about him as an individual, but they had plenty to say about his clan. Passionate. Unique. Driven. Those were the words they used when they knew he could hear them. When he eavesdropped, they mostly stuck to one word. Crazy.

And that was before his older brother had killed the rest of the clan and fled the village. These days he was more likely to get sympathy than a suspicious look. He found both equally irritating.

No matter what, though, Sasuke had refused to let himself be defined by others. He would chart his own path in life. He didn't have to overcome any bad blood or curse of darkness. He simply refused to believe any of the nonsense spouted by foolish outsiders who didn't know the first thing about his clan.

Now, looking at his brother, Sasuke felt the first stirrings of doubt begin to creep into his heart.

Team Seven had been returning from the Land of Waves when they walked into an ambush. One of the two attackers hadn't made much of an impression. Sasuke had noticed blue skin and an ordinary looking flak jacket before the man had barreled into Kakashi with his sword out. The two of them were still battling off in the distance. The man must be skilled to keep the famous Copy-Nin occupied for so long, but Sasuke didn't spare him a second glance. His attention was fixed on his brother, who he had last seen dressed in the simple but functional ANBU uniform.

Itachi had changed since he had seen him last. He was wearing a voluminous black cloak. Silk sprayed out from the hem and sleeves, decorated with bloody moons. The cloak itself was embroidered with an eyewatering pattern of red lines that hinted at a sinister purpose. Most strangely, his left eye was covered by an embroidered eyepatch, though there was no sign of a scar on his face.

Itachi was standing on top of a rock beside the road, his right hand splayed out to the side, and his left arm bent so that the small ball of fire hovering over his hand obscured his right eye from sight. He was calm, as though he didn't consider the ninja before him to be worthy of his attention.

Sasuke shook himself out of his stupor and roared, sending a grand fireball towards his brother. Beside him, Naruto and Sakura both charged forward, looking to take advantage of the opportunity to attack.

As the fireball reached Itachi, though, Sasuke felt it ripped from his control. The ball of fire wavered, before flowing like water to form a halo circling above Itachi's head. At almost the same moment, Itachi lashed out with his right hand, slapping Naruto and Sakura away with contemptuous ease. The two of them tumbled to a halt at Sasuke's feet.

"Itachi," he growled.

"Foolish little brother," came the reply. "You think to challenge me when you don't even know my true name?"

"What?"

"You stand in the presence of Itachiburou Nobunogga, the greatest ninja ever produced by the Kouma clan!"

Following the announcement, he held both of his hands above his head. The fiery halo flowed down to form a ball, then streaked upward, briefly connecting ground and sky with a pillar of flame.

"What are you talking about?"

"You'll find the answers you seek beneath the Naka shrine," Itachi, or Itachiburou, said, bringing his hand down in front of his face. "If you're ready to face the truth."

There was only one question that Sasuke wanted answered. "Why? Why did you do it? What happened that night?"

For a moment his gaze locked on his brother's single uncovered eye. It almost felt like the old days, like there was a shared understanding between them. He almost thought he saw his brother waver for a moment.

ooOoo

Five years earlier...

The Third Hokage was dressed in the full regalia of his office, an apologetic expression on his face. Standing next to him was a middle aged man who was dressed in ordinary clothing, provided that one was willing to overlook the fact that he had torn off his right sleeve and instead wrapped his right arm in black-dyed gauze. The wrappings were decorated with red patterns that almost, but not quite, formed an effective sealing array. The gauze on the back of his palm was marked with the shape of an evil eye.

"I'm sorry, old friend," the Hokage said. "Danzo and the others insisted that we test our active duty ninja for mental instability. If I delayed any longer, it could have led to open revolt."

He really was sincerely apologetic. While others might scoff at the oddities of the Kouma clan, the Hokage treated their leader with all of the respect and dignity that was due to one of the village's founding pillars.

"The Kouma clan has faced grave danger in the past, but always triumphs in the end!" Fugaku Kouma replied, pointing dramatically towards the sky. "This is but a momentary setback."

"I made the test as easy as I could," the Hokage said, "but the penalty for failure is death."

"Of course!" Fugaku proclaimed. "Anything else would be a mockery!"

"Sasuke was too young. Everyone else from the Kouma clan has been tested," the Hokage said. He paused, unable to keep a look of sorrow from his face as he suddenly felt every inch an old man. "Itachi passed."

"I thought that might happen. There always was something strange about that boy," Fugaku said, then sighed. Reaching for an inside pocket, he pulled out a scroll and tossed it to the Hokage. "After the test, please give him this."

"I-" the Hokage began, but Fugaku held up his hand. With the other, he pulled out another scroll.

"This is for you," he said, waiting until the Hokage took it from his hand. "A last request."

"The test is scrupulously fair. I can assure you-"

"Yes, yes," Fugaku said, "let's get on with it."

Resigned, the Hokage opened the door in front of him and led the two of them into a small room. The only furniture was a small table, located in the center of the room. Atop the table were two items. One looked like nothing more than a glass bead, tinted a fiery red. The other was a small black box.

"This is the crystallized power of a tailed beast," the Hokage said, gesturing at the bead. "It's perfectly safe to handle. If you eat it, the power of the tailed beast will incinerate you from the inside out. If you drop it into the box, the seal inside will render the bead harmless."

"I see," Fugaku said. He eyed the table, but didn't move.

"The test is to dispose of the crystal safely," the Hokage said. "Let me be clear: the box is in no way locked or booby trapped. It is perfectly safe to open, and will render the crystal harmless."

"Hmm," Fugaku said, rubbing his chin. "Very interesting."

"If you eat it, you will die," the Hokage said. "If you put it in the box, you'll pass the test."

"Is that an order?" Fugaku asked.

"No. I can't give you an order right now," the Hokage said, feeling the despair seep into his old bones.

"Don't worry," Fugaku said. "I know what I have to do."

Without another word, he picked up the crystal and popped it into his mouth, swallowing it down in a single smooth motion. The Hokage's shoulders slumped, and he brought a hand up to massage the bridge of his nose.

"Yes! I can feel it! The crimson flames burn within!" Fugaku cried. "Power beyond power! To break through the edge of madness! This is the true ninja way! Ahahahahahahahaha-"

His laughter was cut off by a bright flash. An instant later, a pile of ashes was all that was left of the leader of what had been one of the greatest clans in Konoha.

The Hokage sighed, then unrolled the scroll that he had been given. He should have known that Fugaku would want to shape the aftereffects of the disappearance of his clan. As much as he didn't want to get caught up in another of Fugaku's schemes, it was, after all, the last wish of an old friend.

ooOoo​

The moment of connection passed, and his brother's gaze turned mocking.

"You're not ready to know."

It was the last straw. Sasuke's self control snapped. He drew a kunai and charged forward. He'd been training hard since he graduated from the Academy. Even more so after Kakashi finally started teaching them for real, after Haku. He was stronger and faster than he ever had been before.

It didn't matter. His brother parried every attack with a single hand, then sent him flying with a backhanded slap. He went flying and crashed into his teammates, only staying on his feet because they grabbed his arms in support.

"Foolish little brother. You haven't even begun to embrace the power of your heritage," he said, before reaching for the patch over his eye. "I beseech thee, chaotic hellfire slumbering within this body, born from the primeval darkness. Devour mine enemies! The time is right, come forth and torment this complacent age!"

As he pulled the eyepatch free, there was a flash of dark movement. The forest that had served as Kakashi's battlefield had suddenly been consumed by a ball of black flame. There was a great crash as tree trunks fell to the ground. The few trees that fell towards the black fire puffed into ash as soon as they made contact.

Itachi-or whatever his name was-swayed on his feet. He would have fallen to the ground if his blue-skinned partner hadn't suddenly appeared by his side. He unceremoniously slung Itachiburou over his back, but Itachiburou's expression remained locked in a satisfied grin.

"A true ultimate attack leaves one helpless afterward. Come find me when you understand."

An instant later, they were gone.

"That was your brother?" Naruto asked, clearly in disbelief.

"He used to be normal."

"It's typical for the Kouma clan," Kakashi said, appearing by their side scorched, but otherwise unharmed. "The highest masters of the bloodline can deny reality and replace it with their own, but they aren't exactly normal people."

He looked at the shocked faces of his students and smiled, tapping the forehead protector over his eye. "I learned a few things when I picked this up, you know."

"Then," Sakura began, then paused, hesitant. "Does that mean that Sasuke..."

Kakashi hummed, looking amused. "Probably."

"Wow," Naruto said, clapping Sasuke on the should, "I always thought you were a boring stick in the mud, but your family is pretty cool."

Sasuke looked down at Naruto's hand. Even after all this time as teammates, he still didn't understand why the other boy thought that he wanted his approval.

Sakura stepped forward and lowered herself into a formal bow. Surprised, Naruto took a few steps away from them.

"Sasuke, I apologize," Sakura said. "I never should have pressed my affection onto you once you made it clear that you weren't interested. It will never happen again."

Sasuke stared at her, feeling off balance. It was true that he found her annoying. Even more so when she was asking him out. He should have been relieved. Some instinct though, warned him that this was the first sign of great danger. That his future happiness was in grave jeopardy.

He knew exactly who to blame. His fists clenched in rage.

"I will never give up! I will have my revenge!" Sasuke declared. "I can feel it burning through my veins. My heart beats for vengeance!"

"That's good," Kakashi said, nodding, "don't try to deny your nature."

Sasuke fell to his knees and screamed at the sky.

ooOoo​