The chaotic burst of white light subsided. The six heroes, utterly spent but triumphant, stood in the sterile void.
"The Nexus Core is reset, the dimensions are secured. Return to your respective timelines," the Arbiter's voice declared.
Jin-Woo looked around, counting heads. He, Gojo, Tanjiro, Saitama, Okarun, and Kazuma. Six.
"Wait," Jin-Woo commanded, his eyes narrowing. "You said the Nexus Seven. The seventh member is the new anchor. Who is it?"
Gojo, having recovered just enough to be obnoxious, surveyed the space. "I didn't see anyone else in here. Did we accidentally create a sentient dust bunny? Maybe Kazuma's perpetual bad luck condensed into a little cursed creature?"
Kazuma bristled. "Hey! My bad luck is an essential, high-utility asset!"
Suddenly, the air in the center of the void rippled, not with chaotic static, but with a profound, almost literary sense of melancholic tragedy.
A new figure materialized.
He was a slender, handsome young man wearing a simple, white button-down shirt and black pants. He had dark, wavy hair and an expression of utter, soul-deep exhaustion. He looked around the pristine white void, sighed with profound disappointment, and then fixed his dark eyes on the ceiling.
"Ah, this cruel fate," the figure muttered, his voice smooth and melodramatic. "I thought, perhaps, that the destructive unification of all timelines would finally grant me true, beautiful oblivion. But instead, I've been yanked into this dazzling, agonizing white space, wearing odd cloths. Even the universe denies me a graceful exit."
"Who the heck are you?" Saitama asked, genuinely confused.
"I am Osamu Dazai," the man replied, bowing slightly, his gesture overflowing with self-pity. "And you, clearly, are the cruel agents of my continued, pointless existence."
The Arbiter's holographic sphere appeared directly above Dazai, confirming his identity.
"Osamu Dazai is the seventh entity, the Nexus Anchor," the Arbiter explained. "He is the perfect conceptual compromise. His singular power, No Longer Allowed in Another World, is the ability to negate any and all supernatural or magical effects from other dimensions."
Gojo's eyes widened. "Wait, he nullifies magic? If I used my Cursed Energy near him, it would just... fail?"
"Precisely," the Arbiter confirmed. "He is the Ultimate Anti-Anomaly. His presence ensures that when your worlds overlap, your powers do not glitch or destroy the fabric of reality. He is the bridge, the firewall, and the exit sign."
"So, he's basically the ultimate party pooper," Kazuma summarized, clutching his Pocket Dimension.
Dazai merely sighed. "If my only purpose is to prevent beautiful tragedy and ensure the tedious continuation of life, then yes, I suppose that makes me a party pooper."
Tanjiro rushed forward, his face etched with genuine distress. "Dazai-san! You must not speak that way! Your life has value! Your sorrow is so intense, I can smell it! Please, let me help you find happiness!"
Dazai looked at Tanjiro's sincerity, momentarily stunned. "Ah, the pure heart of the young hero. It's almost sickeningly brilliant. Please, stop smiling. It suggests the universe is not the empty, meaningless husk it truly is. If you wish to see me happy then kill me."
Okarun moved around Dazai, eyes spinning, analyzing his spiritual signature. "Man, his aura is heavy. It's like a cloud of pure, concentrated literary anguish. He's not possessed; he's just... super depressing. The vibes are completely shot."
Jin-Woo looked at Dazai, recognizing a strange kind of ultimate power in his negation ability. "A non-magical, absolute counter to all high-level skills. The Arbiter's training was perfect. We need him to enter his own dimension."
Gojo grinned, instantly sizing up the negation ability. "So, the strongest Sorcerer alive needs a moody novelist to travel between worlds? That's rich. Don't worry, Dazai-kun. I'll make sure your life is extremely annoying and hard to end."
Saitama just yawned. "Can he fly? If he can get us home quickly, that's fine."
"Dazai is your new anchor," the Arbiter concluded, as Dazai takes pills like thier the most tastiest treats. "To return to your home dimensions, you must focus your collective intent through him. However, know this: now that the seven of you are conceptually linked, any one of you can, with great effort, follow Dazai to another member's world."
Kazuma's eyes widened with financial terror. "Wait! So, Gojo can randomly show up in my world and steal all my loot?"
"And Jin-Woo can accidentally summon a giant, talking frog to his S-Rank Gate," the Arbiter added helpfully.
"This is my worst nightmare!" Kazuma screamed.
Jin-Woo stepped up to Dazai. "Anchor. Take me home. To my Shadow Domain."
Dazai gave a profound, mournful sigh, placing his hand over his heart. "Very well. Let us continue this farce called existence. It will be profoundly tedious, I assure you."
He focused his unique, anti-supernatural energy. A brilliant white gate, stable and clean, snapped into existence behind Jin-Woo.
One by one, they stepped through: Jin-Woo first, then Gojo, laughing maniacally, then a determined Tanjiro, followed by an exhausted Okarun and a terrified Kazuma. Saitama simply walked through, focused on finding a supermarket.
Dazai stood alone in the pristine void, the last one remaining. He smiled, a genuine, albeit melancholy, smile.
"Perhaps... an eternal link to six hyper-active idiots is the one form of suffering I had yet to explore. It might be interesting. But first..."
He turned and, using the last of the Nexus energy, opened a portal that didn't lead to a dimensional home, but to a beautifully decorated, high-rise balcony.
"A nice, long fall would be a perfect capstone to this entire affair."
And with that, Osamu Dazai, the perfect, depressing Nexus Anchor, stepped out of the white void, ready to cause existential chaos across the multiverse.