The mysterious underwater prison called Impel Down is situated in the calm belt. Together with Marine Headquarters and Enies Lobby, it forms a triangular shape, with massive whirlpool currents flowing between it.
To successfully enter Impel Down, the massive gates known as the "Gates of Justice" must be opened to let the currents flow in. If the gates are closed, ships can only circle in the whirlpool, and ordinary pirate ships must detour.
The prisoners sent here are either famous pirates or high-ranking marines.
Impel Down has six levels, with stronger prisoners on deeper levels.
Pirates like Anderson, with a bounty of just over a hundred million berries, are usually held in the fifth level, the Freezing Hell.
When the warships of Akainu and Gion arrived, a peculiar man in a black coat came to greet them.
"Hello, I am Magellan, the Chief Warden of Impel Down."
The man named Magellan had two weapons on his head that looked like horns, and he carried bat-like wings on his back, making him resemble a demon from Western mythology.
Magellan was originally the Deputy Warden of Impel Down.
After the Golden Lion Shiki escaped from Impel Down, the former Chief Warden and Head Jailer resigned in disgrace, resulting in a sudden leadership overhaul in the prison.
Despite his fearsome appearance, Magellan was surprisingly kind and friendly: "May I ask, what level of prisoners have you brought this time, Vice Admirals?"
"I've brought the Anderson Pirates. Captain Anderson has a bounty of 130 million berries, and the rest are under a hundred million."
"I have similar prisoners."
After listening to Akainu and Gion's introductions, Magellan quickly made arrangements: "Alright, I will personally escort those with bounties over a hundred million to the Freezing Hell, and the others can be handled by Hannyabal and sent to the Blazing Hell (Level Four)."
"If there's nothing else, I need to get back to work and can't accompany you further."
Magellan is a Paramecia-type "Venom-Venom Fruit" user, which has severe side effects – frequent diarrhea.
The unfortunate Chief Warden spends nearly 10 hours a day in the bathroom. With eating and sleeping, his working hours are miniman, Impel Down has the position of Head Jai to assist the Chief Wardenler.
However, since the previous Head Jailer retired, the new Head Jailer, Shiryu of the Rain, turned out to be a bloodthirsty maniac who often killed prisoners without reason.
To ensure the safety of the prisoners, Magellan avoids delegating work to Shiryu unless necessary, as new prisoners might be killed before reaching their cells.
"It seems we are not needed here. Let's return to Headquarters."
Akainu, thick-skinned as ever, moved closer to Gion, acting as if the earlier incident had never happened.
His persistence and shamelessness in pursuing women were almost exemplary, but unfortunately, Gion had never intended to give Akainu a chance.
Efforts in the wrong place are futile.
"I want to take a tour of the prison."
Hailan didn't leave and instead expressed his desire.
Akainu was puzzled: "This place is filled with vicious criminals. What's there to see?"
Hailan justified himself: "If there is a place in this world that gathers the most ferocious pirates, it's not the Four Seas or the New World, but this underwater prison."
"It's rare to visit here. If I don't experience the presence of these dangerous criminals, how can I face the beasts outside the cages in the future?"
It did sound reasonable.
"Sounds logical, but..."
Akainu looked at Gion, unwilling to be separated from the lovely lady because of Hailan.
Gion ignored Akainu's gaze: "I think Hailan makes a good point."
Since Hailan was a child in the navy port, Gion, being Zephyr's student, often played with him.
Women naturally like children; to Hailan, Gion was like a big sister.
Although the relationships were a bit complicated...
Hailan called Gion his sister, and Gion called Vice Admiral Tsuru; her sister and Vice Admiral Tsuru were from the same era as Zephyr.
So, technically, his father became his big brother.
Fortunately, people don't focus much on family ranks and usually address each other by name.
Otherwise, it would be pretty hard for anyone to adapt.
In any case, Gion's words often supported Hailan.
"Tina, this is a rare opportunity. Go with Hailan and see the infamous pirates in the prison."
"Just be cautious, though. In the sixth level, Eternal Hell, there are many pirates with Conqueror's Haki. If you're not mentally prepared, don't go to the sixth level."
Conqueror's Haki–Hailan had only experienced it once.
It's a sign of the "King's potential," appearing in one in a million people.
Conqueror's Haki is a mental assault technique that can instantly knock out those with weak wills.
Five years ago, when the Flying Pirate Golden Lion Shiki stormed Marineford, Hailan personally felt the impact of Conqueror's Haki.
To be honest, it was an unpleasant experience.
Luckily, Hailan had been in the rear navy port at the time. If he had been near the battlefield, he might have been knocked unconscious.
Five years ago, after the capture of Pirate King Roger (who had turned himself in but was officially claimed to have been captured by Garp), Golden Lion couldn't accept that the navy had defeated his lifelong rival. Like a mad lion, he stormed Marineford alone.
That day, Golden Lion, wielding the famous swords Oto and Kogarashi, fought desperately against Admiral Sengoku and Hero Garp.
To Hailan, who came from Earth, this battle was like a clash of titans, giving him a clear understanding of the world's top combat power.
In addition to his unparalleled swordsmanship, Golden Lion was a Paramecia-type "Float-Float Fruit" user, capable of flying freely and controlling non-living objects at will.
Countless sword lights filled the sky, creating a scene of carnage.
Flying warships, terrifying tornadoes...
Golden Lion turned Marineford into a sea of corpses and blood.
But ultimately, he was defeated by the combined might of two top-tier warriors.
Golden Lion Shiki cut off his legs two years later and became the first person to escape from Impel Down, earning his place as a legend.