"So this is the research base for the summoning beasts on the island?" Uchiha Nagi asked, standing before a large mountain. The cliff face appeared unremarkable, but it was a clever disguise, reinforced by a sealing jutsu to repel any potential attackers.
"Yes. One moment, I'll open the door." Uzumaki Honoka stepped forward and deactivated the seal. A gate slid open, revealing a base with a surprisingly sci-fi aesthetic.
Perhaps because she had grown up on the island with no contact with the outside world, or perhaps because he had just saved her life, Uzumaki Honoka answered whatever Uchiha Nagi asked without a hint of caution.
"I'm Uchiha Nagi," he said. "You can call me Nagi, or Nagi-nii, if you like."
"Oh, okay... Nagi-nii." Uzumaki Honoka nodded, the blush still warm on her cheeks. The masculine scent from when he'd held her seemed to linger in the air.
"By the way, do you have any idea which nation's ninja built this place?" Nagi asked, his curiosity piqued. Establishing a research base this far out at sea was no small feat; it was beyond the capabilities of any minor power.
"I don't know. They never wore forehead protectors. After they invited my mother here when I was little, we just stayed. She never told me which village hired us before she passed away."
"Then, a few years ago, there was an accident. The ultimate summoning beast broke out of the lab. Everyone was killed... the guard-nin, too. In the end, my mother sacrificed herself to seal it..." As she spoke, her expression darkened. For a girl with no father, losing the only family she had ever known was a crushing blow.
"I'm sorry," Nagi said gently. "I didn't mean to make you recall such painful memories."
"It's alright, Nagi-nii. It's been several years," Honoka said, shaking her head. "Anyway, since you weren't sent by them, you should probably find a time to leave. I don't know how much longer I can maintain the seal on my own."
Her voice grew grim. "If it breaks the seal, it will be a disaster for the entire ninja world. My mother's dying wish was that I must never let it escape..."
"If I leave," Nagi asked, "what will you do?"
Honoka lowered her head, leading him deeper into the base. Though large, the facility was spotless, a testament to the girl's diligent upkeep.
"I'll find a way to seal it for a few more years," she said. "Maybe then it will be weak enough to be killed. If I can just push it into the island's volcano... into the lava... it should die."
As she explained, Nagi quickly pieced it together. The ultimate summoning beast wasn't a Tailed Beast. The Tailed Beasts were unique, born from the Ten-Tails' chakra and the Sage of Six Paths' Yin–Yang Release. They could be sealed for centuries without food or water and not die because they were, in essence, part of the God Tree, which could absorb natural energy from the world and convert it into chakra.
But the ultimate summoning beast was a man-made creature, a biological entity like Gamabunta. It had not yet evolved to the point where it could survive by absorbing natural energy; it lacked the God Tree's ability. Therefore, it had to eat.
Having been sealed by Honoka's mother for several years, it was already severely weakened. Another decade or two of being sealed, and it might just starve to death. That was why it was desperately battering against the seal—it was a biological imperative to survive, to break free before it died.
And Honoka could only helplessly reinforce the seal day after day. Like Nagato, she was constantly overdrawing her life force to produce the chakra needed to keep the beast contained. She had been doing this for years...
Nagi looked at Honoka's pale, bloodless face and the dark circles under her eyes. It was obvious she hadn't had a proper rest in years, all for the sake of maintaining the seal. And she had been constantly depleting her chakra during her formative years... At seventeen or eighteen, she was as thin and frail as a girl of fourteen.
"You're constantly overdrawing your chakra," Nagi observed. "If you keep this up, you won't live much longer."
"It's fine. This is the mission my mother entrusted to me. Nagi-nii, if you have nothing else to do, please rest here for the day and leave the island tomorrow. This place isn't safe. If I lose control and it escapes..."
"Don't worry," Nagi said with a faint smile. "I'm here now. I'll help you deal with it."
"But..."
"I know sealing jutsu, too."
"Really?!" Honoka's eyes lit up with surprise and hope.
"Of course. And my chakra reserves are much larger..." Nagi released his chakra in full. The atmospheric pressure skyrocketed, soon reaching the level of a Tailed Beast. It couldn't compare to the Nine-Tails, but it was certainly a bit more than the One-Tail.
Honoka's jaw dropped in astonishment.
As they walked through the base, Honoka unreservedly showed Nagi everything. There were many documents she couldn't understand; she wasn't a researcher or an expert like Orochimaru. She and her mother had simply been there to use their sealing jutsu to guard against summoning beast riots.
Many of the records had been lost in the accident, but Nagi was still able to find some remaining data. He was confident it would be useful. It seemed this trip hadn't been a waste. This island, isolated in the middle of the ocean, could also evade the detection of White Zetsu. It was the perfect location for a base.
Nagi made a decision. His first major stronghold in the ninja world would be right here. He could conduct his research and training, and later, he could head to the Land of Sky to seize their Sky Fortress...
Nagi walked onto the sealing platform. "Honoka," he said, "open the seal. Let me see what this ultimate summoning beast can do."
A worried look crossed Honoka's face. "But... what if we can't stop it...?"
Nagi just smiled faintly. His red Mangekyo flared to life, and the spectral form of a half-body Susanoo materialized in the base. Staring up at the giant constructed from pure chakra, Honoka finally believed him. She nodded and moved to open the seal.
"Relax. If it cannot be tamed as a summoning beast, I will destroy it myself."
As Honoka cautiously released the seal, a beast brimming with all kinds of negative energy began to smash its way out of the sealing platform.
Crack!
CRACK!
With a final, shattering sound, the ultimate summoning beast broke completely free.
"RAAAAWWRR!"
It let out a furious roar. It was so hungry.
Nagi's first impression upon seeing it was, What the hell is that thing? It's fucking hideous.
How could they have created such a grotesque summoning beast? A monstrous, insect-like creature stood before him. It had a gaping maw on its abdomen, reminiscent of No-Face, and its head was a mess of tentacles and fangs. The limbs of several different animals protruded from its body. It looked like a giant, standing cockroach.
[Hungry... so hungry...]
The enormous ultimate summoning beast—no, it was more like a giant, standing cockroach—met his gaze. From its compound eyes, Nagi could read a single, overwhelming message: it was starving, hollow...
"Mangekyo Sharingan." Nagi activated his dojutsu, attempting to control it.
"RAWR!" The giant cockroach struggled for a moment before spitting a spiderweb at him.
It failed.
The Mangekyo's genjutsu, an ocular power that could even subdue the Tailed Beasts, had failed on this summoning beast. It gave Nagi a very strange feeling. It was as if a random assortment of parts had been crudely smashed together. In its mind, there was no soul...
"ROAR!"
The giant cockroach roared at Nagi, unleashing a powerful wave of genjutsu-like psychic energy, which Nagi's Mangekyo instantly repelled.
"This thing can use genjutsu?" Nagi said, incredulous.
"Look out!" Honoka's voice cried from the side.
Nagi glanced over and saw the giant cockroach gathering an immense amount of lightning from its head, aiming it directly at them.
Ninjutsu? This thing knows Lightning Style? Nagi's jaw nearly hit the floor. He instantly leaped away, grabbing Honoka and pulling her into his arms as he jumped clear.
"It can absorb the abilities of any creature it eats! Be careful! That Lightning Style belonged to a guard-nin it devoured!" Honoka explained urgently.
"Wood Style: Deep Forest Emergence!" Nagi called out, using the ninjutsu best suited for subduing Tailed Beasts.
Swoosh—
The wood that had just bound the giant cockroach instantly crumbled into a pile of ash on the ground.
"Watch out! It evolves to counter a ninja's attacks!" Honoka cried out.
"How unexpected," Nagi mused. "Wood Style, which can absorb the chakra of the Tailed Beasts and suppress them, is actually having its own chakra absorbed and being countered by a summoning beast."
Nagi was amazed. The nearly infallible Wood Style was useless against this ultimate summoning beast. Of course, it was possible his own level was too low and he had only created a small grove. If it had been the First Hokage's sea of trees, with its vastly superior quality and power, subduing it wouldn't have been a problem.
"If that's the case, then I'll use Susanoo."
Nagi's Mangekyo Sharingan spun, and a colossal Susanoo rose to its full height. The seemingly massive ultimate summoning beast, still in its infancy, only reached its knee.
Sensing the danger, the so-called ultimate summoning beast immediately turned to flee. As it ran, it began to evolve, two large bulges sprouting from its back.
Squelch!
A pair of wet, dripping wings tore through its flesh.
"Don't let it get away! It's trying to go outside to feed!" Honoka shouted.
"Relax. It's not going anywhere. Destructive Death: Air Type!" Nagi commanded his Susanoo, closing the distance in just a few strides.
Raising the Sword of Totsuka, he lopped off the beast's wings, causing it to let out a pained shriek.
But that wasn't enough to kill it. Nagi frowned and sliced it in two. He hadn't expected it to be like a cockroach in both appearance and vitality.
Even after he'd sliced it in two, both halves were still writhing with life. What shocked Nagi even more was that it seemed to have absorbed a portion of the chakra he'd channeled into the Sword of Totsuka...