Duel Academy had barely recovered from the chaos of the First Seal. The training island was under quarantine, guarded by elite duelists and sealed with sacred barriers. But the air remained heavy, tense—like the pause before a storm.
In the infirmary, several students who had come into direct contact with the corrupted spirits remained unconscious. Their dreams were locked in cycles of repeating duels against faceless shadows. Nurse Fontaine and Bastion worked tirelessly, but nothing broke the trance.
"They're trapped in some kind of dream loop," Bastion explained to Chancellor Sheppard. "Their minds are sealed off… like someone hijacked their REM cycles with duel energy."
Sheppard's eyes narrowed. "Gate II…"
Elsewhere, deep within the ruins of the ancient Sleep Shrine in northern Europe, Veylorn stood before a massive obsidian arch embedded with glowing runes.
Each rune pulsed in rhythm with the dreams of those asleep around the world.
He raised the second key—a Duel Monsters card etched with dark mist and twisted dreamcatchers: "Oneiric Serpent - Uroboris".
"Dreams are the gateway to all souls," Veylorn intoned. "Through fear and fantasy, I command thee—Gate II, break."
He slammed the card into a stone slab.
The ground shuddered as a web of darkness burst into the sky, spreading like ink across the dreamscape of the world.
That night, at Duel Academy, Kaito jolted upright in bed.
But something was wrong.
His dorm was… different. The shadows were too long, the air too still. His Blue-Eyes card hovered above him, glowing faintly.
Then he heard it: whispering. Familiar voices chanting in reverse.
Kaito stepped out into the hallway—but found himself standing in the old KaibaCorp tower, the duel arena where Seto Kaiba once made history. Spectators lined the stands, unmoving. Their faces were blank.
A massive Duel Disk towered at the far end. And across the field stood himself, cloaked in a twisted version of his Obelisk Blue uniform, eyes burning violet.
"Let's duel," the nightmare-Kaito said with a smile. "You lose, you stay here forever."
In the real world, Jaden gasped awake, drenched in sweat.
Winged Kuriboh hovered near him, frantic.
"They're attacking through dreams!" the spirit squeaked.
Jaden grabbed his Duel Disk and bolted out of bed. "We need Kaito—now!"
But when he reached Kaito's room, the door was locked by a spiraling ward of shadow-energy. Alexis and Zane arrived seconds later.
"We've seen it before," Zane said grimly. "The Seal of Dreams. It was rumored to exist during the old Duel Spirit Wars, but no one ever confirmed it."
Alexis placed a palm on the ward. "It's feeding off Kaito's own mind. We can't break in… but maybe we can go in."
Jaden nodded. "I've dream-linked with Winged Kuriboh before. If I sync my energy with Kaito's card, I might be able to dive into his dream."
Zane looked hesitant. "It's risky. If you get stuck…"
"I won't," Jaden said. "He'd do the same for me."
Within the dream world, Kaito and his nightmare double clashed.
Blue-Eyes White Dragon roared across the field, but the twisted version countered with Oneiric Serpent - Uroboris, wrapping the battlefield in illusions and fear-constructs.
Kaito's life points dropped steadily. The dream distorted, walls melting into dueling arenas from his past lives.
"Give in," the nightmare hissed. "You're afraid. You know what you're becoming. A Monarch of your own design."
Kaito gritted his teeth, summoning Azure-Eyes Silver Dragon to his field. "No. I'm more than a weapon. I'm more than a vessel."
The two dragons collided—blinding light against endless shadow.
At that moment, Jaden burst into the dream, riding Winged Kuriboh like a comet.
"Need a tag partner?" he grinned.
Together, the two duelists launched a joint assault, summoning Elemental HERO Neos and Blue-Eyes Twin Burst Dragon.
In a combined attack, they shattered the illusion, and with it, the nightmare-Kaito. The Seal pulsed—and cracked.
The dream collapsed.
Back in the real world, Kaito gasped awake. The shadow ward vanished, and the room returned to normal.
Alexis and Zane pulled him out, just as Nurse Fontaine reported that the other unconscious students had awakened.
"The Seal of Dreams has been broken," Bastion confirmed moments later. "But only temporarily."
Kaito looked out the window at the rising moon. "Veylorn knows we're onto him. He'll move faster now."
In the Arctic wastes, Veylorn stood over the frozen remains of the second gate.
"You survived. Impressive."
He raised the next key.
"Then let's see how you handle the Gate of Wrath."