The skies over Duel Academy darkened unnaturally. What began as drifting clouds quickly swelled into a stormfront thick with arcane interference. The Obelisk Blue tower's beacon flickered—its spirit wards faltering under the pressure of the rupture forming in the east.
Kaito stood on the cliffside path near the academy's shoreline, watching the energy swirl over the horizon like a spiraling hurricane of shadow and fire. His Duel Disk pulsed rhythmically, sensing the unnatural presence spreading across the world.
Behind him, footsteps approached. Alexis, Jaden, Bastion, and Zane had arrived.
"It's starting," Kaito said without turning. "The first of the Six Seals… was broken."
Jaden glanced at the black lightning in the clouds. "You sure that's not just weather gone crazy?"
"No," Bastion replied grimly. "I analyzed the energy. That's not atmospheric—it's metaphysical. Spirit pressure of this magnitude hasn't been recorded since the early Duel Terminal incidents."
Alexis asked the question everyone was thinking. "Where will they strike first?"
Before Kaito could answer, the academy's main intercom crackled.
"All students and faculty—emergency alert. This is Chancellor Sheppard. Spirit Realm breach detected on the Duel Academy training island. All dueling staff, report for defense immediately."
Zane didn't hesitate. "We move now."
The training island, a forested terrain used for simulation duels, had become a battleground. Trees warped with abyssal energy bent toward the sky. At the island's center, a fissure in reality pulsed, and from it emerged monsters that had no classification—twisted mockeries of Duel Spirits: a corrupted Elemental HERO, a skeletal Buster Blader, and a Blue-Eyes with eyes filled with ink-like darkness.
Kaito and his team arrived at the edge of the island via hover skiff. The moment they stepped off, Duel Disks activated instinctively.
"Kaito!" yelled Syrus, waving them down. He was defending a group of first-years with Hassleberry. "They're not obeying summoning rules! They're just… appearing!"
Alexis drew her deck. "Then we don't wait. We counter with force."
Kaito summoned Blue-Eyes White Dragon, the creature roaring with righteous fury. Across the field, the corrupted clone mirrored the call, but its echo was jagged—distorted.
"Synchronize," Kaito ordered. "We battle in rotations. Bastion, cover Syrus. Jaden, take the left flank with Alexis."
"What about you?" Jaden asked.
"I'm going into the rift."
Jaws dropped.
Zane stepped forward. "Are you insane?"
Kaito locked eyes with the breach. "They want us to play defense. But we need to understand their origin—what the Shadow King is truly planning."
Zane hesitated, then handed Kaito a glowing token. "Emergency beacon. If it gets too deep… don't play the hero."
Kaito nodded.
With a deep breath, he sprinted forward—diving through the breach as Blue-Eyes roared after him. The rift consumed them both in silence.
Inside the rift was nothingness—an endless plane of crumbling Duel Monsters cards. A graveyard of lost spirits, where duel remnants echoed like ghosts.
Kaito hovered in this space, surrounded by whispers of ancient duels. Then, a presence revealed itself.
A figure, regal yet monstrous, sat upon a floating throne of chained cards. The Zeroth Monarch.
"So you came. As expected."
Kaito gritted his teeth. "You're behind this. You shattered the First Seal."
"No," the Monarch replied. "Veylorn did. I merely lent him power. But he is no servant—he is a harbinger of your world's reckoning."
"Then tell me what you want."
The Monarch raised a chained hand. "The Six Seals hold back the origin of duel energy. A force older than humans or spirits. When they are broken, all realms will converge—spirit, shadow, mortal."
He leaned forward, glowing eyes burning into Kaito's soul.
"And from that chaos… the true game begins."
With a wave of his hand, the Monarch expelled Kaito from the rift. In a flash, Kaito was thrown back into the training island, landing hard as the corrupted spirits retreated.
The sky began to clear—but the damage was done.
Zane rushed to his side. "What did you see?"
Kaito struggled to sit up. "The Shadow King… he's not trying to conquer the spirit realm. He's trying to merge it with ours."
Alexis's voice was quiet. "Then the First Seal is just the start."
Kaito nodded. "And we have five left."
Far away, in the ruins of a sunken city, Veylorn stood before another ancient monument.
Gate II: The Seal of Dreams…
He pressed the Forbidden Deck to the stone.
"Shatter."