The journey back was brief.
Arthur's thoughts spiraled between power and the multi-faceted layers of transformation he was about to undertake.
Once he arrived back in the safety of his own territory, he settled himself in an empty room and prepared his instruments.
The meticulous process began as he opened himself up and merged the cells with his body.
While all of it might have seemed simple, he was concentrating hard, having remembered the knowledge of his past surgeries. Be it Yukimi Iburi, Ranmaru, or Haku, Arthur was no stranger to being one of the best transplant surgeons in this world.
The procedure commenced swiftly as he ever so carefully guided the cells by channeling his chakra to facilitate the joining of their inorganic ions and carbon-containing molecules. He felt the union occurring—the foreign essence melding with his own in a manner that would leave earth's physicians speechless.
No more than an hour passed, and the throbbing beneath his skin felt like a second heartbeat.
He had done it—he'd successfully incorporated Karin's cells, and now it added a new reservoir that promised growth.
When he finished, he took a moment to breathe.
'So this is a Uzumaki's blood…' he thought.
The transformation felt complete, yet the tasks that lay ahead demanded more focus. So he searched his body for the newly acquired chakra by probing gently within the folds of his inner self.
There it was: a distinct new layer added to his pool of chakra, the signature unmistakably that of an Uzumaki.
Yellow light from the Gift of the Hermit chakra flickered brightly as it blended with Karin's essence. It felt almost as if the waters were trying to break free. But it remained calm. His own chakra pool was also larger and waving with even more potential, like a vessel rejuvenated.
With the Uzumaki techniques closer than they'd ever been, he pondered the next steps.
Balancing the chakras would be fundamental; flourishing would depend on his control over them. It would also require more finesse. Control, to be exact.
What this newly expanded chakra pool allowed was for the better use of performing sealing techniques. That meant it was time for practice.
✟
The same day, Arthur ventured into the wooded area behind his home, where the trees made an ideal setting for his training, and a clearing opened up before him, allowing sunlight to filter through the leaves overhead.
He took a relaxed breath by centering himself in the tranquil surroundings.
In the depths of his mind, he recalled the moments that shaped Karin's ability to summon special "Adamantine Chains."
The Adamantine Chains were written to be unique sealing chains primarily associated with the Uzumaki clan. These same chains were emblematic of the clan's prowess and were connected to their chakra.
Users could summon them from their torso (and other body parts), allowing them not only to restrict and immobilize targets but also to neutralize their chakra, making them vital for subduing stubborn opponents.
This extraordinary resilience was illustrated by the fact that even the Nine-Tails, one of the most powerful Tailed Beasts, found it challenging to destroy them.
From what Arthur recalled, the chains were shown to have the capability to nullify the chakras of the beings they bind, rendering them incapacitated. This dual functionality—both physical and chakra-based—added versatility to the technique, making it effective in a wide array of combat scenarios.
One other interesting aspect of utilizing the Adamantine Chains was the user's flexibility in their deployment.
Instead of summoning a full array of chains all at once, experienced users could choose to create only a few, allowing them to extend and spread underground to cover a broader area.
That tactic would help maintain a clutter-free environment while enabling users to establish a significant range and control in battle by catching adversaries off guard or springing traps or restraining someone from unexpected angles.
Another noteworthy application of the chains was the ability to erect barriers.
Kushina Uzumaki, during her time as the Nine-Tails' Jinchūriki, showcased this skill by creating an impermeable barrier to prevent the Nine-Tails from escaping and simultaneously keeping other ninjas at bay, such as Hiruzen Sarutobi.
Karin highlighted them through her manifestation of a similar ability. Described as a glimpse of Kushina's original technique, Karin used what's known as the "Golden Chain: Bonding" technique, which allowed her to produce chains for offensive purposes.
And despite being labeled as an incomplete version of the Adamantine Sealing Chains, her technique proved formidable when she effectively used it to destroy parts of a giant wood statue created from Hashirama's wood style.
That alone was enough to showcase their raw potential behind this clan's sealing techniques.
Now, to actually use the chains, most Uzumaki had to face emotional trauma—much like Karin had.
Yet that was never Arthur's route.
Emotion was not something he indulged in, nor was he interested in courting chaos to summon power. Still, the Uzumaki techniques, especially the chains, beckoned to him.
What he desired to do was summon these trademark chains through the sheer will of his chakra.
So he focused his mind, feeling the new Uzumaki chakra intertwining with his existing chakra, like vines climbing a sturdy tree. Extending his palm forward, he channeled that feeling by envisioning the chains coiling and manifesting from his chakra.
There was a subtle twist and pull in the air at first. Then it happened: a swirl of pale chakra exploded from his palm before manifesting as a golden, slender, gleaming chain. It shot forth and coiled around a nearby tree by snaking around the trunk with surprising speed.
Yet it was not the massive chains he remembered them to be. It was light, almost frail, like a shadow of its intended form. Though it held the tree firmly, he could feel its limits.
Kushina's chains were sturdy, long, and large enough to bind a three-hundred-foot behemoth. Karin's was no different. But Arthur's? His chains probably couldn't even knock a kunai out of the air!
'Interesting,' he thought, perusing the chain as it returned to his body. 'More practice's needed…'
Not at all troubled by their size, he continued his training.
He worked on the techniques until dusk began to scorch the horizon with shades of orange and purple. Again and again, he summoned the chains by pushing out bursts of chakra that sent them spiraling to encircle trees, boulders, and even small animals that sometimes fled too swiftly for the chains to catch.
The chains tethered those objects into place, but they always reverted to their ethereal state before he could harness more than a fleeting grasp of their real power.
Over the course of that long evening, he found pace in the movements; he began to unlock deeper nuances of control. While the chains no longer felt like a stranger tearing at his essence, there still needed to be that sense of the chains acting as an extension of himself.
Only small, flimsy constructs could be produced. But to his surprise, the chains had begun to thicken and grow a little longer than when he first summoned them.
As the final rays of sunlight began to fade into twilight, Arthur now felt exhausted from overusing his chakra.
The best thing he had managed was binding a large stone, nearly the size of a boulder, while holding it in place as if it were a child's toy. Solid, but not a Tailed Beast.
'To think that Uzumakis had something this potent,' he thought to himself, ending his training.
Taking into account all the remaining Uzumakis, only one person had the potential to use these chains: William. Naruto could probably manifest them also, but it was never shown in the series.
William, however, had an insane amount of chakra. While he never outrightly showed Arthur that he could summon the chains, that did not mean that he wasn't capable of drawing out their power.
Arthur didn't like that idea.
After a few hours of rest and having his chakra restored, he was ready to train the chains again!
Why wouldn't he continue practicing?
These chains had to become mammoth-like for them to be considered truly potent in combat.
For the whole night, he trained and trained until his chakra depleted over and over again.
Then it happened; there was a change in the chains' structure. As he looked at them, they seemed to have grown thicker beyond their original spectrum.
To confirm, he shot out his chains once more, and they enveloped an entire tree, causing it to splinter under the pressure of their hold. But he wasn't done. As moonlight cascaded through the treetops, he shot the chains up and expanded them like a vine searching for the sky.
Ching-ching-ching!
Smaller links surged forth from the main chain, creating audible cracks that impinged on the ground.
When Arthur looked, he understood what this technique was: the "Golden Chain: Barrier" technique. It was the same move Kushina had used to erect a barrier that had stopped the Nine-Tails.
Yet the amount of chakra inside the metal seemed weak.
"We're not done yet," Arthur hoarsely whispered. He tried to summon more chains to make the barrier powerful, but suddenly, his chakra waned and he collapsed to the floor. The shimmering chains soon broke apart before dissolving back into his body. "Dang it..."
The chains—his chains—were indeed as weak.
As he lay there on the moonlit floor, he closed his eyes to recover.
Things weren't all bad. These chains could one day bind a Tailed Beast if he simply trained more and gained a deeper understanding of their chakra flow. If he did that, he was confident that he could surpass both Karin and Kushina.