Submit beneath these eyes!

'So this is the Underwater Great Prison?'

Xi Yan, sitting in the sea, looked at the huge building in the distance, a hint of surprise appearing in his eyes.

How did they manage to build such a large prison underwater?

Was it built in advance and transported here using special abilities, or was this place still land hundreds of years ago?

However, due to rising sea levels, this area has been submerged by seawater.

Thinking of this, Xi Yan looked down at the seabed below.

'It depends on the depth of the water... the latter is more likely...'

Perhaps sea levels are rising very quickly in this world.

After observing for a while, Xi Yan withdrew his gaze.

Then, he turned his gaze toward the Gate of Justice behind him.

After they entered, the Gate of Justice began to slowly move, and now it's almost closed.

'It seems I can't leave through the Gate of Justice anymore,' Xi Yan thought to himself.

Of course, if the Gate of Justice Switch is inside Underwater Great Prison, he could use his Sharinggan to control the other party to open the door.

By riding the special ocean current, we can quickly leave this place.

'Looks like we'll need to find the switch to control this place once we get inside.'

As he pondered this, Xi Yan swam toward the Erha.

'Next, I need to figure out how to infiltrate,' Xi Yan thought, stroking his chin. 'I'll try using my Transformation Technique.'

If even the Transformation Technique doesn't work, the only option is to use the Sharinggan to control some people and bring them in.

Just then, Xi Yan noticed a change at the Underwater Great Prison.

Suddenly, a Great Gate opened in the wall very close to the sea, revealing yellow lights.

The next moment, several creatures resembling giant Blue Elf, wielding Giant Axe, rushed out from inside.

They then searched the water for Sea Kings they could attack.

Seeing this, Xi Yan narrowed his eyes.

'So there's an entrance underwater...'

Glancing at the Great Gate with its yellow light on, Xi Yan grinned, thinking, 'This really... provides me with a great infiltration spot.'

Watching the giant Blue Elf rapidly chasing after the Sea Kings, Xi Yan thought for a moment and created a Shadow Clone with a small amount of Chakra allocated to it.

After nodding to Xi Yan, the Shadow Clone silently rushed off into the distance, eventually hiding among the warships and silently watching the direction of the Underwater Great Prison Great Gate.

Once Hancock successfully leaves, the Shadow Clone will disappear on its own, relaying the information to Xi Yan.

Meanwhile, Xi Yan activated Transformation Technique, turning himself into a shark, and then silently rushed towards Broggly in the distance.

At that moment, several Broggly surrounded a Sea Kings and then launched an attack.

"Puff!!"

"Puff!!"

"Puff!!"

The sharp Giant Axe easily sliced through the opponent's eel-like body, turning it into huge, round pieces of meat.

Then, these Broggly seized their target and turned to rush back the way they came.

Just then, a Broggly noticed the shark approaching from the side, which startled him.

Broggly:???

Are there really fish that small here?

Although I don't know what happened, it wouldn't be a problem to grab this guy and take him away.

With that thought in mind, Broggly quickly rushed towards the shark.

However, the moment he got close, Broggly felt a blur before his eyes, and then he saw a pair of incredibly terrifying eyes appear in front of him!

Broggly:!!!

'What... what the hell is this?!'

After this thought crossed his mind, Broggly was subdued by Xi Yan.

'Hmm, the plan is going smoothly.' Xi Yan, using Broggly to shield himself, glanced at the gap above and thought, 'Looks like these guys aren't as quick-witted as I thought; they didn't even notice their companion was separated from them.'

After shaking his head, Xi Yan controlled the Erha to swim over, then grabbed the Broggly and rushed into the Erha's mouth.

The moment it returned to the Erha's mouth, Xi Yan withdrew his Ninjutsu.

"Xi Yan?"

Seeing Xi Yan return, Luffy asked with delight, "How did it go?"

"There's no time to explain now, you come out first."

"Oh."

Although he didn't know what Xi Yan was going to do, Luffy obediently came out of the warehouse.

Without wasting any words, Xi Yan immediately put the warehouse into the scroll and then put it back into his Ninja Tool Bag.

After finishing this task, Xi Yan looked at Luffy and said, "Luffy, next I need to enter the sea so I can get into Underwater Great Prison."

"Take a deep breath, and don't make a sound until I call you out, understand?"

"I understand!" Luffy said.

"Good."

Xi Yan nodded, then activated his Transformation Technique, turning into Broggly's appearance.

After casually picking up the other person's axe, Xi Yan stuffed Luffy into his clothes.

"Luffy, I'll count to three and then I'll charge out. Get ready."

"Good!"

"1...2...3!!"

"Splash~"

The moment Xi Yan finished speaking, Erha opened its gaping maw and let the seawater in.

The powerful flow of water swept Broggly, who was inside the mouth, straight down.

However, Xi Yan was not affected in the slightest. He rushed out of the water at top speed and arrived at the special pool of the Underwater Great Prison.

"Bang!"

Xi Yan, bursting through the water, rushed out carrying a large piece of meat.

"Finally back."

Seeing the last Broggly return, the jailer breathed a sigh of relief and then said to his companion, "Close the hatch."

Although it's unclear why this Broggly returned so late, since it's already back, there's no need to keep the hatch open.

Soon, under the control of the jailers, the huge hatch gradually closed, completely isolating the seawater from the inside and outside.

"Thank you for your hard work. Take the meat to the Cold Storage Room on the first floor," the jailer said to Xi Yan.

Xi Yan didn't answer, but instead glanced at the interior of the room.

'Are there only two people...?'

Thinking of this, Xi Yan put down the meat in his hand, looked at the two jailers, and said, "Look me in the eyes."

"Bang!"

As soon as Xi Yan finished speaking, he returned to his original appearance.

The two jailers instinctively looked into Xi Yan's eyes, and then realized that something strange seemed to have appeared in their vision.

"Submit to these eyes!"

"Clang!"

Mangekyō Sharingan, activated!

The two prison guards were immediately charged!

After the two were restrained by Xi Yan, Luffy also fell off Xi Yan's body and landed on the ground.

"Snap~"

"Huff... huff..."

Luffy, panting heavily, seemed to have survived a close call.

He had just been pinned down by Xi Yan's hand inside his clothes, unable to move an inch, and almost suffocated.

However, Luffy didn't blame Xi Yan, after all... it was for the sake of the infiltration operation!

"That's enough," Xi Yan said. "I've got these two under control."

"I see."

Luffy, adjusted his hat, and got up from the ground. He turned around and looked around, asking, "Where am I?"

"It must be the special exit used for hunting in the Underwater Great Prison," Xi Yan said.

So far, he hasn't found any other use for it.

"Let's go, let's go save Ace!" Luffy said.

"Don't rush, before that, we need to find out where Ace is," Xi Yan said.

After speaking, Xi Yan turned his gaze to the two jailers and then asked, "Tell me, where is Fire Fist Ace being held?"

"Fire Fist Ace is a heinous criminal with a bounty exceeding one hundred million, so... he will be imprisoned on the Level 5!"

"The Level 5?"

Xi Yan stroked his chin and asked, "How many floors are there in total?"

"Fifth Floor."

The guard paused for a moment after speaking, then continued, "However, there are also rumors that there is Sixth Floor in Underwater Great Prison, but Warden Magellan has never publicly acknowledged this."

Upon hearing this, Xi Yan was taken aback for a moment, then frowned and said, "Rumor... you are a jailer here, yet you don't know if this is true or false?"

"I'm sorry, I've only heard such rumors and cannot confirm their veracity," the jailer said.

Hearing the other person's words, Xi Yan paused for a moment, then turned his gaze to another jailer and asked, "And you?"

"Me too."

Listening to their conversation, Xi Yan rubbed his temples and said, "In that case, we'll have to catch a big fish and ask him."

These two people are controlled by the Mangekyō Sharingan, so what they say is credible.

To Xi Yan's dismay, the ordinary prison guards knew very little.

Never mind, let's just say there's Sixth Floor.

As for how to get to the Sixth Floor, you'll find out after you catch the big fish.

After shaking his head, Xi Yan said, "Tell me how to get to the Level 5."

"The guards at Underwater Great Prison use elevators to travel between Fifth Floor, but there are also Den Den Den Mushi) in the corridors and elevators used for surveillance. The images they capture are transmitted to the monitoring room in real time."

"Surveillance Den Den Mushi?"

Xi Yan was taken aback. This world even had Den Den Mushi) specifically for surveillance?

No, how many uses does this thing actually have?

There are all sorts of Den Den Mushi) – some make calls, some listen in, some are designed to prevent eavesdropping, some take photos, some even act as webcams.

"Yes, Surveillance Den Den Mushi." The guard nodded and said, "Once a prisoner appears on the screen, the guard in the monitoring room will pull the alarm, notifying the guards on that floor to deal with the escaped prisoner."

"In that case, we'll have to avoid those surveillance cameras," Xi Yan said, stroking his chin.

Otherwise, there's a possibility of conflict with the most powerful person in Underwater Great Prison.

However, if Ace is not rescued, there is no point in clashing with the other side.

Thinking of this, Xi Yan asked, "Is there any way to bypass the surveillance cameras in the corridor?"

If we can avoid the surveillance cameras, taking the elevator will get us downstairs the fastest.

"No, that won't work." The jailer shook his head and said, "The surveillance cameras in the elevators and corridors will never be turned around. They're guarded 24 hours a day. There's no way to hide."

"Most importantly, the elevator is currently in use, and it's still unknown how long it will take to get up."

"Used?"

"Yes," the jailer nodded and said, "The Pirate Empress, Boa Hancock, came to visit Underwater Great Prison, and she went down via the elevator."

"I imagine she should be reuniting with Warden Magellan by now."

The fact that Boa Hancock was coming to visit Navy Headquarters was something all the jailers on the ground floor knew.

"Warden Magellan..." Xi Yan pondered for a moment and said, "Is this guy the strongest in this Underwater Great Prison?"

"Yes."

"How strong is he?" Xi Yan asked. "How does he Admiral?"

"Warden Magellan's strength is terrifying. As Devil Fruit User, he's invincible here!" a guard said. "We all believe he's no weaker than any of the Admiral!"

This piqued Xi Yan's curiosity; was that man really that powerful?

Or perhaps... this jailer is rather inexperienced and unaware of just how terrifying the Admiral's strength truly is?

However, one thing Xi Yan is certain of is that this warden named Magellan definitely has the power to suppress the pirates here!

Otherwise, I wouldn't deserve to be called invincible.

"The Venom-Venom Fruit..." Xi Yan said, "A guy whose whole body is poisonous, huh?"

"Yes."

"Lord Magellan is Poison Man ate the Venom-Venom Fruit," the jailer said. "And what he likes to eat most are all kinds of deadly poisons."

"But because of the high toxicity, I get diarrhea every day."

Xi Yan:...

Is this considered a side effect of Devil Fruit ability?

Do I have diarrhea every day?

A guy who gets diarrhea Tenten can suppress the pirates here... This guy must be pretty strong!

but...

'Please, I hope I don't run into that guy.' Xi Yan muttered to himself.

It wasn't that he was afraid of the other party's strength, it's just... he was afraid of getting beaten to a pulp by the other party, that would be too disgusting.

"Can't we go yet?" Luffy asked.

"You idiot, I told you not to rush," Xi Yan said irritably. "How can I save people if I don't figure out how to get to the Level 5?"

If they don't even know how to get there, they'll just be going around in circles in this Underwater Great Prison.

Sooner or later the navy will discover us, so we must figure out the route down below.

"All right..."

Seeing Luffy sitting down obediently Luffy waiting, Xi Yan shook his head, then looked at the jailer and said, "Besides that elevator, is there any other way to get to the lower floors?"

"Some."

The jailer nodded and said, "Each floor has a Great Gate, and behind that Great Gate is a spiral staircase. You can reach the next floor by going through that spiral staircase."

"However, a key is needed to enter the Great Gate; without it, there's no way to open that incredibly heavy Great Gate."

Even if they wanted to open that heavy Great Gate, it would take several people working together.

Of course, this is assuming you have the key.

If you don't have the key, don't even think about opening the Great Gate.

"An incredibly heavy Great Gate?" Luffy grinned upon hearing this, "This thing can't stop us."

Both he and Xi Yan possessed immense destructive power; smashing a Great Gate would be incredibly easy for them.

"Don't think of things so simply, you idiot," Xi Yan said. "We could destroy the door, but that would attract other enemies as well."

"Then it won't be infiltration, it will be a forced entry!"

If a Marine Admiral to provide support... then rescuing them would become extremely difficult.

With a powerful warden and a Marine Admiral, rescuing someone from prison would be incredibly difficult.

Therefore... if possible, Xi Yan hopes this operation will be carried out in secret, preferably by rescuing the person quietly!

"I see." Luffy scratched his head and said, "Okay, I got it."

Thinking about it carefully, it seems to be like this.

"Where are those main Great Gate located?" Xi Yan asked.

"The first floor is in the southwest corner," the jailer said. "I've seen the Great Gate from that location."

"The first floor?" Xi Yan frowned. "What about the other floors?"

"Have no idea."

"And you?"

"I don't know either."

"How come you know nothing?!" Xi Yan said speechlessly.

"We're new here, having only arrived a month ago. We've been staying on this floor and have never been downstairs, so we don't know where the stairs to the lower floors are."

Xi Yan had a bit of a headache. Could it be that he was afraid these guys would be captured by pirates and leak information, which was why he hadn't told them too much?

Thinking about it carefully, it's actually quite possible.

Let's go to the next level and grab another jailer to question.

After shaking his head, Xi Yan continued, "Where is the key to open that Great Gate?"

"As for the key..." the jailer thought for a moment and said, "It should be with Warden Magellan."

Xi Yan:...

Isn't that awkward?

To get the key, you have to confront Magellan, and confronting Magellan might mean being surrounded by Marine Admiral... This is just too much of a headache.

No wonder Grandma Za said that the Underwater Great Prison was a place that was said to be absolutely impossible to breach.

With such vigilance in their defenses, it would be impossible for an ordinary person to rescue someone from here quietly.

"Sigh... it seems the only option is to try using Wind Release to cut an opening," Xi Yan said.

If all else fails, we'll just have to fight our way through.

'Hmm, as long as all the witnesses are eliminated, it will be a perfect infiltration,' Xi Yan thought to himself.

"So, in the end, we still have to force our way through?" Luffy stood up and asked.

If it's a problem that requires fists to solve, then leave it to him.

"Not exactly," Xi Yan explained. "If we could cut a hole in the door silently, we could also sneak up to the next floor."

I wonder what material that Great Gate is made of. If it's all made of Sea Stone, then it would be quite difficult to cut it open with Wind Release.

"To cut an opening..." Luffy glanced at the Kusanagi Sword at Xi Yan's waist, then nodded and said, "When do we set off?"

"Now."

Xi Yan glanced in the direction of the Great Gate and said, "I'll send these two out to check the situation. We'll go out after we've made sure no one else is there."

Then, Xi Yan guided the two guys outside, carefully surveyed their surroundings, and nodded to Xi Yan after confirming that no one else was around.

"Yes, it's safe outside."

"It seems this isn't a place for daily activities," Xi Yan said, stroking his chin.

That makes sense; after all, this is the fishing spot of that big Blue Elf, and ordinary people don't need to come here.

"Let's go, Luffy."

"They're here!"

Following behind Xi Yan, Luffy quickly entered the corridor and looked around.

"This place looks huge..."

"Of course, after all, it's the Underwater Great Prison that holds countless pirates," Xi Yan said with a smile.

According to Shakky-jie, this Underwater Great Prison may have existed for hundreds of years, imprisoning countless pirates during that time.

If there wasn't enough space, it would have been burst open by pirates long ago!

"Should we take them with us?" Luffy asked, glancing at the two jailers.

If they bring these two people with them, the chances of them being discovered will be much higher.

"I've hypnotized them both," Xi Yan shook his head and said, "Don't worry about them, they won't leak our information."

The jailer controlled by the Mangekyō Sharingan could not possibly break free of the control on his own.

If Xi Yan wanted to, controlling the other party to commit suicide wouldn't be a problem.

"All right."

"Um..."

Looking at the two jailers, Xi Yan considered for a moment, then said, "Do you know where the Gate of Justice Switch is located?"

"I know." The jailer nodded. "The Gate of Justice Switch is in the Power Room on this floor. We go there often."

Before Fire Fist Ace was imprisoned, a batch of pirates would be sent here every few days, so the Gate of Justice needed to be opened.

And the two of them would sometimes be on duty there.

"That really is... effortless!" Xi Yan grinned and said, "Tell me the location."

Having found a way to open the Gate of Justice, they could escape from here as quickly as possible.

"It's in the Southeast Corner of the first floor," the jailer said.

As they spoke, the jailer pointed out a direction to Xi Yan so that he could confirm the exact location.

Glancing in the direction the other person was pointing, Xi Yan squinted and said, "There... Okay, I understand."

"You two just pretend you didn't see us, go about your business."

"Yes!"

The two jailers nodded, then walked down the corridor without looking back to continue their unfinished tasks for the day.

After watching the two leave, Xi Yan looked at Luffy and said, "Luffy, let's go find that Great Gate."

"Profound!"

"Idiot, don't shout so loudly," Xi Yan said irritably. "We're on someone else's turf, you know that!"

"Oh..."

Ignoring the idiot, Xi Yan looked towards the distant corridor, squinting his eyes as he said, "Hopefully, we can successfully infiltrate the Level 5 this time."

If we can avoid fighting, it's best to avoid it, after all... Hancock is right here!