The Grand Line's Calm Belt stretched endlessly under a cloudless sky. The sea lay unnervingly still, its surface a mirror of stagnant water untouched by even the faintest breeze. A medium-sized blue warship emerged from the turbulent currents of the Gates of Justice, its sails slackening as it lost the driving force of the wind.
Without hesitation, the warship activated its Sky Island-produced Breath Dial, mounted at the stern, and the paddle wheels along its sides. Propelled by these mechanisms, it surged forward across the eerily calm sea. After what felt like an eternity, Sephiroth, standing at the bow, finally caught sight of a formidable structure—a ring-shaped fortress surrounded by twenty warships. Impel Down.
The prison fortress was divided into an outer and inner circle, connected only by a drawbridge. Its security system was ruthlessly efficient, equipped with countless surveillance den den mushi and fearsome jailer beasts. Known as the "Bronze Wall and Iron Fortress," Impel Down was organized into six levels, each descending deeper into the earth.
The lower the level, the more dangerous the criminals housed within. The sixth level was reserved for the most terrifying offenders—those whose escape would plunge the world into chaos and unrest.
As the warship docked at Impel Down's gate, Sephiroth disembarked alongside Domino, Admiral Akainu, and Admiral Aokiji. Though Fleet Admiral Sengoku had granted Sephiroth permission to execute Byrnndi World himself, the presence of two Admirals made it clear that Sengoku remained wary of him.
The massive Sea Stone-inlaid iron gate of Impel Down groaned as it slowly rose. Two towering wooden doors swung open, revealing a towering figure clad in black. Standing five meters tall, with black wings and two horns protruding from his head, this was Magellan—Impel Down's Warden and a Paramecia-type Poison-Poison Fruit user.
Magellan's very existence was toxic. His body was composed entirely of poison, and even the air he breathed carried lethal venom. The potency of his fruit was so overwhelming that it affected even him, forcing him to spend nearly ten hours a day in the throes of diarrhea. After accounting for eight hours of sleep, Magellan had only four hours left for work.
According to Domino, Magellan's Poison-Poison Fruit had reached Awakening, allowing him to generate vast quantities of poison at will. His toxins were so potent that even Armament Haki users couldn't immunize against them. Within the confines of Impel Down, Magellan was virtually unstoppable in a one-on-one fight.
Sephiroth speculated that in the original timeline, Blackbeard's defeat at Magellan's hands was likely due to overconfidence. Blackbeard had assumed his Armament Haki could neutralize the poison, never anticipating the sheer lethality of Magellan's abilities—toxins that nearly wiped out the entire Blackbeard Pirates.
"Long time no see, Admiral Aokiji! Admiral Akainu! And this must be Sephiroth, right? Nice to meet you!" Magellan greeted them in turn, his voice booming. But before he could continue, a sudden gurgle erupted from his stomach.
Magellan clutched his abdomen, his face twisting in discomfort. "Hiss~! Domino, I'll leave the rest to you. I need to go to the toilet first..." Without another word, he dashed across the drawbridge, vanishing into the inner circle fortress.
Sephiroth's lips twitched as he watched the Warden's abrupt departure. With a mix of amusement and disbelief, he muttered, "Your Warden is really... really... working hard!"
Domino adjusted her reddish-brown glasses, her face impassive as she spoke in her black jailer uniform.
"No," she said flatly. "He's been dealing with diarrhea for years now—he should be used to it by this point. If anything, it's us subordinates who suffer. We have to pick up the extra work the Warden can't handle because of his condition, which significantly increases our workload."
Under Domino's guidance, the Vice Warden led the three of them into Impel Down without incident. After the routine inspection, they took the elevator down to the sixth level, where the most notorious criminals were imprisoned.
Normally, all visitors were required to surrender their weapons to the Impel Down guards for safekeeping. However, since Sephiroth was here under special orders from Marshal Sengoku to carry out an execution, he was permitted to keep his dual swords. "Where's Ace being held?" Sephiroth asked casually. "I'd like to take a look while I'm here."
The moment the words left his mouth, Admiral Akainu and Aokiji turned their attention to him, and the atmosphere grew noticeably heavier. Aokiji scratched his head, looking uneasy.
"That wasn't mentioned in the orders I received..." he muttered.
"I advise you not to do anything unnecessary," Akainu said coldly.
Sephiroth clicked his tongue. "Why are you two looking at me like that? Relax, I won't cause any trouble. I just want to go over and chat for a bit," he said, his tone teasing.
Domino, sensing the tension escalating, stepped in quickly to mediate. "Admiral Akainu, Admiral Aokiji, the path to Byrnndi World's cell passes by Ace's. Sephiroth will see him sooner or later."
"That's right," Sephiroth chimed in. "I just want to have a quick chat with Ace while I'm here. With the two of you watching, what could I possibly do?"
Akainu and Aokiji exchanged a glance but said nothing more, allowing Sephiroth to proceed. As they passed a cell, Sephiroth caught sight of Ace, bound in sea stone shackles and thick iron chains, alongside Jinbe, one of the Shichibukai.
"Well, well," Sephiroth said with a smirk. "Isn't that Jinbe? What are you doing here?"
Jinbe glanced at him, his expression stoic. "The Marines conscripted me to fight against the Whitebeard Pirates. But Fish-Man Island owes a great debt to Whitebeard, so I refused out of principle. That's why I'm locked up here."
"I see," Sephiroth said with a sigh. "You're a man of integrity, aren't you?"
Jinbe's stubbornness was well-known. Given his sense of honor, it was unlikely he'd ever betray his principles, even if it meant being imprisoned. Sephiroth wasn't planning to rescue him—he was just here for the spectacle.
After exchanging a few words with Jinbe, Sephiroth turned his attention to Ace, who looked battered and weak. The smile faded from Sephiroth's face, replaced by a cold indifference.
"Ace," he said. "Long time no see. I have to ask—do you regret going after Blackbeard?"
Ace let out a bitter laugh, his voice heavy with despair. "How could I not regret it? Now I've dragged Whitebeard and the others into this mess."
"Is that so?" Sephiroth replied, his tone chillingly calm. "How about I give you some good news? Besides the Whitebeard Pirates, the Beasts Pirates and the Big Mom Pirates—three of the Four Emperors—are preparing to launch a joint attack on Marineford. They're using your execution as the catalyst for a world-class war."
"Given the scale of this execution, you've surpassed even Pirate King Roger! In a way, you've already achieved your dream—standing at the pinnacle of pirates as you set sail. I doubt any pirate execution will ever match the grandeur of this moment," Sephiroth remarked, his tone laced with playful sarcasm.
"The pinnacle? Is that so?" Ace replied with a bitter chuckle. "Honestly, hearing you say that makes me feel... almost honored."
"You mentioned unfulfilled wishes earlier," Sephiroth continued, a sly grin spreading across his face. "If there's something you still want done, I might consider helping you achieve it."
Truth be told, Sephiroth hadn't anticipated this. Ace, who hadn't made much of a splash when he first set out to sea, had somehow become the catalyst for a world-shaking conflict—Marine versus the Three Emperors and their pirate crews. The scale of this war dwarfed even the Marineford War from the original timeline.
According to intelligence gathered by Nico Robin, the Whitebeard Pirates had mobilized over ten thousand fighters. The Beasts Pirates and Big Mom Pirates weren't far behind, sending fifty thousand and thirty thousand troops respectively. Combined, the three pirate crews fielded roughly a hundred thousand fighters, matching the Marine's numbers.
But the real advantage lay in the sheer number of mid-to-high-level combatants among the Four Emperors' forces. Their commanders outnumbered the Marine's Rear Admirals by two to three times. Even the Whitebeard Pirates alone, with their captains and affiliated crews, far surpassed Marineford's Rear Admiral-tier fighters. It was no wonder the Whitebeard Pirates had managed to hold their own against the Marines in the original timeline, despite being outnumbered.
This war would inevitably leave the Marines severely weakened, regardless of the outcome. Depleting their mid-to-high-level combatants would be a blow to the World Government itself—something Sephiroth found deeply satisfying. When the Umbrella Corporation eventually clashed with the World Government, the pressure would be significantly lighter.
For that, Sephiroth felt genuine gratitude toward Ace. As for saving him? That was another matter entirely. Whether Ace lived or died in this war was up to fate. Sephiroth had no intention of intervening too much. He'd already given Ace advice and warnings. If Ace still ended up in this predicament, he had only himself to blame.
Ace opened his mouth to speak but hesitated. His gaze flickered to Admiral Akainu and Aokiji standing beside Sephiroth. Instead, he forced a weak smile and said, "Can I at least get a proper meal before I die? I've been locked up for so long, surviving on a cup of water and a bowl of rice a day. I'm starving!"
"Is the food in Impel Down really that bad?" Sephiroth asked, turning to Domino with raised eyebrows.
"To prevent prisoners from escaping, we only provide the bare minimum needed for survival. It's a rule of Impel Down," Domino explained, adjusting her brown glasses. Her tone was firm, though her confidence wavered. "Even if it's your request, Sephiroth, I can't break the regulations."
Sephiroth noticed the unfriendly gazes from Admiral Akainu and Aokiji, so he could only shrug his shoulders, saying somewhat helplessly:
"Is that so? Forget it then. Sorry, Ace — I can't grant this wish for you." With that, Sephiroth gestured for Domino to lead on. The group descended deeper into the sixth level until they reached a massive cage.
Inside, a refrigeration unit hummed steadily, pumping cold air into a glass cube to preserve the massive block of ice within. Frozen inside was a burly man with a horned helmet and a grayish-green beard — Byrnndi World. Domino unlocked the iron gate, and Sephiroth stepped inside.
Akainu and Aokiji moved to follow, but Sephiroth raised a hand to stop them. "Wait outside," he said. "It's cramped enough as it is. With you watching over my shoulder, I won't be able to work freely." Reluctantly, the admirals stayed outside with Domino, ready to witness the execution.
The moment Sephiroth turned, thick black mist surged from his body, engulfing the cage and obscuring the surveillance den den mushi. The air filled with the sharp cracks of shattering ice and the piercing screech of bats. The noise was deafening.
Akainu and Aokiji focused their Observation Haki, sensing Byrnndi World's life force fading steadily through the mist. When the darkness finally cleared, Byrnndi World lay in pieces, blood pooling across the floor.
Seeing this, Admiral Akainu and Aokiji couldn't help but mutter to themselves, wondering what kind of feud had driven Sephiroth to such brutal extremes. What they didn't realize was that the gruesome display was merely a smokescreen — a distraction to conceal his true goal of extracting the Devil Fruit power from Byrnndi World's blood.