The Mountain

"Huff... Huff..." Hikaru took deep breaths.

He was standing in a fairly lush jungle, surrounded by towering ancient trees and various treehouses. Around these structures bustled peculiar lifeforms in strange garb—some in full wizard robes, others in sci-fi tech gear. Despite their wildly different outfits, they mingled harmoniously with no sense of discord.

"Lord Amagi, are you feeling any discomfort or unease?" Captain Crystal stood before Hikaru, seemingly having waited for some time—upon seeing Hikaru arrive, he asked.

"Don't worry, I already checked everything," Tierra floated beside them, glancing around.

Despite her assurance, Hikaru still gave himself a once-over. After confirming he was in one piece, he bounced lightly on his toes to test his energy.

"Hmm—seems fine?" Hikaru said, stretching out his body.

He looked up at the symbol behind him: a green sigil, unlike the usual dark dimensional gates—the very portal that he had arrived through in this world.

Naturally, Hikaru was now in the place he'd visited once before—the Village of Spellcasters.

After building his own dimensional gate, Hikaru first had Captain Crystal teleport over, using the Emerald Book to maintain communication and confirm his safety.

After a few successful tests, he began human transmission.

Throughout the process, the Philosopher's Stone ensured Captain Crystal could be forcibly pulled back; Otherwise, Hikaru wouldn't have risked a "spirit-body experiment."

Thankfully, Professor Banner's guidebook, "An Idiot-Proof Dimensional Gate Blueprint," proved easy and reliable. As long as the process was followed correctly, everything worked fine.

Compared to the school's limited-use gates, building and managing his own meant greater autonomy. Given Hikaru's high spirit compatibility, he could now handle a couple of dimensional trips a month harmlessly, letting him travel to other dimensions outside of Academy-sanctioned use.

Now that the gate was complete, he could do this every month.

If his compatibility improved or Tierra regained more components, his monthly limit might increase.

Of course, the latter wasn't easy since Hikaru lacked the rare materials Tierra needed—just creating "Pirmais" last time had cost him a rare KaibaCorp card, Genex Controller. Until he acquired more base materials, restoring Tierra was on hold.

Hikaru found the Magical Scientist, who was busy with a large experiment. Only after it ended did Hikaru get to explain recent events.

Surprisingly, the Magical Scientist was fully supportive of Hikaru's plan to co-invest ramen tech with his Instant Fusion Cup Ramen—All he wanted was regular updates on product sales.

Of course, Hikaru wouldn't freeload; He signed a contract allowing mutual access via the Emerald Book, syncing the scientist's computer to the human world and sharing half the profits.

While many spirits had no use for human currency, the Magical Scientist had an interest in buying tools and samples from that world.

So he agreed without reluctance.

More importantly, Hikaru had come to this dimension for one major reason:

A card trade with the Magical Scientist.

While last time, he hadn't had the chance, this time, Hikaru brought excess cards like Fusion Substitute, Metalfoes Fusion, and Gem-Knight Fusion to trade.

The scientist was eager to study them and, in return, opened his binder for Hikaru to pick missing Fusion Monsters.

After the fusion of his card Galaxy Serpent into Armityle the Chaos Phantasm, some of his cards had become linked to The Dark - Hex-Sealed Fusion and others to Fusion Monsters like "Sea Monster of Theseus".

While searching through the binder, Hikaru finally found a copy of the Fusion Monster Dark Fiend Skull Dragon, useful as Instant Fusion material or for situational plays.

Its effect restricting Flip Summons wasn't bad either.

Hikaru then brought up something he hadn't had the chance to ask before, "How exactly did the Spirit World break?"

As a high-ranking spirit, the Magical Scientist frowned and shook his head.

"It's not that I don't want to tell you," he said helplessly. "Though I have some standing in the Village of Spellcasters, back when it happened, I was deep in research and missed the whole phenomenon.

After that, the Three Sages investigated it directly; even so, each of them encountered strange events. Crowley even went berserk and nearly became a monster, if not for a passing alchemist who saved him."

So that was it.

Hikaru now had a better idea of how Professor Banner met Aleister.

"Since then, the collapse of the Spirit World became taboo among magicians. Besides, with their ability to travel across dimensions, life went on mostly unchanged. Few had the motivation to uncover those secrets."

"I see."

Hikaru nodded.

After seeing Aster and thinking about the Light of Destruction, he remembered what Vampire Fraulein once said—that the Spirit World was now fully fractured into scattered micro-dimensions.

He'd already suspected Yubel might be behind it—After all, in canon, she caused massive disruption just trying to find Jaden. In this world, she hadn't been launched into space; instead ended up in another dimension.

Her causing trouble there was entirely plausible. So Hikaru planned to ask high-ranked spirits about it.

In the end, no one knew anything.

It looked like he would need to explore the Spirit World himself.

He remembered the first "puzzle" Professor Banner had left him: Coordinates of "The Mountain".

No additional clues. No poetic hints.

Just: The Mountain.

A place where Dragons, Winged Beasts, and Thunder monsters gather!