Connecting his Space with Kaguya's Space was a decision Ryūjin made after careful consideration.
With this link established, if he encountered a situation he could not handle in the One Piece world, he could immediately retreat into Kaguya's space. Likewise, if the Shinobi World faced a crisis that required his presence, he could return instantly.
It was a simple and reliable safeguard.
Kaguya had agreed without hesitation.
"Ryūjin, can Kaguya Ōtsutsuki really be trusted?"
Kurenai Yuhi's voice carried a trace of concern, along with something less obvious.
Linking their spaces required absolute trust. It was not something done lightly. And yet, Kaguya had only been in Konoha for a short time.
Ryūjin shrugged. "Relax. She's not out to screw anyone over."
Based on what he knew and what he had observed, Kaguya had no reason to act against them. Her original goal had always been to prepare for the Ōtsutsuki Clan, nothing more.
Now, with Ryūjin's strength involved, her situation had already changed.
After finishing his farewells with Kurenai, Might Guy, and the others, Ryūjin stopped wasting time.
Three days later.
Inside Konoha's most secure experimental facility, the village's highest-ranking figures had gathered.
Fugaku Uchiha, now the Hokage. Hizashi Hyuga. Shikaku Nara. Several others stood in silence.
Kaguya stood apart from them all.
At the front, Ryūjin faced Orochimaru and Senju Tobirama.
"Open it."
No extra words.
The two moved immediately, activating the technique and locking onto the target world.
The One Piece world.
The portal formed.
The sound of waves echoed through the room as an endless blue ocean appeared within the passage.
Ryūjin had specifically instructed them to select an uninhabited stretch of sea. He had no interest in announcing his arrival.
"Lord Ryūjin, everything is prepared," Orochimaru said.
Ryūjin nodded and stepped forward.
"Take care, Lord Ryūjin," Fugaku and the others said.
Ryūjin gave a brief nod. "Konoha's yours for now."
A Truth Seeking Orb formed instantly, spreading across his body and covering him completely.
His figure turned pitch black.
In the next instant, he vanished.
The portal twisted violently as he passed through it, then collapsed and disappeared.
But before it closed, everyone present saw enough.
Ryūjin had made it through.
---
Above the endless sea of the One Piece world.
A black figure dropped from the sky.
With a soft splash, he landed on the surface of the water, standing as if it were solid ground.
Moments later, the black coating receded, revealing Ryūjin.
He looked around.
Nothing but ocean.
No islands, no ships, no landmarks.
"Great. Straight into the middle of nowhere," he muttered.
Kamui was useless here. He had no reference points to lock onto.
So he focused on something more important.
Testing.
His chakra flowed without issue.
"Good."
He clapped his hands.
"Wood Style, Four Pillar House Technique."
Wood surged outward, twisting and forming rapidly until it shaped itself into a small boat.
Simple and effective.
Ryūjin stepped onto it.
He ran through several techniques in quick succession.
"Water Style, Water Dragon Bullet."
"Water Style, Water Shockwave."
"Fire Style, Great Flame Bullet."
Each jutsu responded perfectly.
No loss of power. No instability.
Everything worked exactly as it should.
"Yeah, nothing's changed."
At that moment, a familiar voice echoed in his mind.
"Ding. Significant change in host environment detected. System updating."
"Ding. Update complete."
Ryūjin raised an eyebrow slightly.
"System update details. In addition to location-based sign-ins, the host can now obtain rewards by defeating designated targets."
"Each target grants rewards only once. Repeated defeats are invalid."
"Low-level targets provide no rewards."
Ryūjin considered it briefly, then gave a small nod.
"Not bad."
This world was mostly ocean, scattered with countless islands. If the system still relied only on locations, it would have been inefficient.
Now, it was far more practical.
Still, most abilities in this world did not interest him.
The Tremor-Tremor Fruit was powerful, but not enough to matter.
His own techniques already matched or exceeded it.
What did catch his attention was Observation Haki.
That level of perception, especially future sight, was something even Sage Mode could not fully replicate.
"Katakuri, Fujitora, Shanks…"
Names ran through his mind.
But first, he needed to figure out the timeline.
Before he could think further, something entered his perception.
A ship.
A pirate ship, approaching from a distance.
Ryūjin did not move.
"Perfect timing."
---
On the approaching ship, chaos and excitement filled the deck.
"Captain Evil Bear, there's a small boat ahead!"
A crew member pointed forward.
A burly man with a thick frame turned his head, grinning.
"Ha! Finally something to plunder."
The ship's sail bore a strange skull emblem with ear-like shapes attached to it.
An unknown crew.
"Move in! I want everyone in the East Blue to know the name Evil Bear!"
His crew roared in response.
One of them hesitated. "Captain, it's just a small boat…"
Evil Bear snapped, "Shut up. Doesn't matter how small it is. We take everything. That's how people start fearing us."
"I ate the Exploding Bear Fruit. I'm going to crush Krieg and take over the East Blue."
His voice grew louder as he spoke, completely caught up in his own hype.
"I'll make the whole sea tremble at my name!"
Among the crew, a young woman with short orange hair watched silently.
Nami.
Her expression carried faint contempt.
"Idiots."
Still, her eyes shifted toward the distant boat.
Then she smirked slightly.
"While they're busy, I'll clean them out."
---
Back on the small boat, Ryūjin watched the ship approach.
He did not bother avoiding it.
"I've got questions anyway."
Within minutes, the pirate ship arrived.
Hooks were thrown, latching onto his boat and pulling it closer.
Before anyone could act, Ryūjin jumped up onto their deck.
The crew froze for a moment.
"…He came up on his own?"
Evil Bear stepped forward, looking him over with interest.
Then he grinned.
"Heh. You've got some guts."