Heroic Spirit Deck in Yu-Gi-Oh!

"Listen closely. Whether it's the spirits of Atlantis or The Great Leviathan of Orichalcos, they only have one target—you, Hoshino-chan."

"Me?"

A completely baffled Hoshino tilted her head, the ahoge on top curling into a confused question-mark shape.

In sync with her, Mana's ahoge twitched like a radar, scanning the area.

"Huh? What's that sound? Am I hearing things now? I'm having auditory hallucinations?!"

The sudden voice of Da Vinci, echoing from the Millennium Bracelet, truly left those unaware of the situation utterly perplexed.

"Shhh, be quiet, Mana~"

Holding a finger to her lips, Yugi didn't fully understand what was happening either. But from the moment the voice appeared—and seeing Hoshino's elated expression—it wasn't hard to tell: this "Da Vinci" must be someone very important to her.

Hoshino pressed for answers:

"But the only one who should be able to command Orichalcos and the undead army of Atlantis is Dartz, right?"

"Not exactly, Hoshino-chan," Da Vinci replied, sounding somewhat troubled.

"The undead soldiers of Atlantis, and the monsters corrupted and mutated by the power of Orichalcos, were originally the citizens of Atlantis from 10,000 years ago. They were human…"

"Humans? Dartz did mention that before."

Using the power of Orichalcos, the once nature-harmonious and simple Atlantean civilization rapidly advanced.

Like the industrial revolution of modern society, this explosive rise in productivity filled the once-pure hearts of the Atlanteans with greed and desire.

Eventually, under the corrupting darkness of Orichalcos, they mutated into grotesque monsters.

"Such a prosperous civilization ending that way… it's truly tragic."

"Calling it an 'end' might not be entirely accurate, Hoshino-chan. Although its form changed, the civilization of Atlantis continued to exist on this planet."

Existing as monstrous creatures may have been the cruelest punishment for a people consumed by their desires.

"So when you defeated the Orichalcos and erased the darkness clinging to this world, that was the true end of the Atlantean civilization."

After Da Vinci's explanation, Hoshino Alter asked:

"So, in this Egypt, Atlantis still existed? But wait, isn't this world supposed to be from the other Yugi's memory?"

If this world was only Yugi's memory of Egypt, then Atlantis—which he had never even encountered—shouldn't appear here.

Da Vinci elaborated:

"The Memory of the Pharaoh. More accurately, it's an independent space created through the connections of the Pharaoh's fate, capable of influencing the real world. The problem lies with this condition of 'fate'…"

"The Pharaoh's fate? What about him? Are you saying this is his fault?" Hoshino shot a suspicious glance at Yugi.

Feeling unjustly accused, Yugi shrank back from Hoshino's accusatory gaze.

"Eh? Don't tell me I'm the reason this is happening?"

"Hoshino-chan, it's good to reflect on yourself more," Da Vinci teased.

"Here, the term 'King' doesn't just refer to the Pharaoh—it also includes the royal lineage of Atlantis… Hoshino Chiyuki."

"The last royal family of Atlantis?!"

Da Vinci dropped a bombshell that left everyone stunned and speechless.

Grabbing Hoshino's wrist, Mana's eyes sparkled with excitement:

"Amazing, Hoshino! That means you're a royal too—just like a prince! Oh, but since you're a girl, you'd be a princess instead!"

"P-Princess…?"

It felt like a title far removed from her. As an ordinary girl growing up, Hoshino had led an entirely unremarkable life for her first 16 years.

However, her father—Dartz's incarnation in middle age—was of the royal bloodline of Atlantis. So, in that sense, Hoshino was indeed the last surviving princess of that ancient kingdom.

A princess who personally destroyed her own fallen homeland.

"Hoshino-chan, during the KC Grand Prix finals, the clash of divine powers activated the seven Millennium Items, creating this world—one formed by both your and the Pharaoh's intertwined destinies."

Even in this "Memory of the Pharaoh" world, Hoshino's memories of Atlantis were limited to the monsters controlled by Dartz. Hence, the world mostly reflected the Pharaoh's memories of ancient Egypt.

"So in the end, the appearance of the Atlantean undead and Orichalcos was my fault… my bad~"

Realizing she had wrongly accused Yugi, Hoshino stuck her tongue out apologetically.

"So this Leviathan… it's really after me? Because I destroyed Dartz and Atlantis 3,000 years later?"

That this crisis—one pushing everyone to the brink of despair—had originated from her actions left Hoshino feeling like a criminal. She couldn't bring herself to look her companions in the eye.

"Hmph. Hoshino, don't tell me you're feeling guilty about all this?"

Kaiba let out a cold snort, his serious gaze fixed on her:

"Don't be so self-absorbed. If you're part of this game, then instead of whining about how hard it is, your job as a duelist is to find a way to win. No one's got time to blame you."

"Kaiba…"

Though his tone was as arrogant as ever, it felt far less grating than usual. Hoshino could tell—he was trying to comfort her in his own way.

"Exactly, Hoshino."

Yugi nodded gently:

"If it weren't for you, we would've lost this Shadow Game long ago. It's because you fought alongside us that we made it this far—to face the final boss together."

"That's right, partner! Sure, technically half the blame is mine too, but…"

Hoshino Alter encouraged her:

"But whether it's Atlantis or the Leviathan, we'll win this final boss fight with style—just like we always do!"

Mana quickly added:

"I don't really get what's going on, but this definitely isn't your fault, Hoshino! You've already done everything you could to protect this world!"

Marlene smiled warmly:

"Since I met you, Hoshino, I've been through more unbelievable things than all my years as a bounty hunter combined. But because of that, I've had the most unforgettable adventures too. Even if everything ends… as long as we're together, there's nothing to be afraid of~"

"Hoshino-chan, no matter what era you're in, you always have incredible companions by your side."

Da Vinci's voice rang out with heartfelt pride. It was precisely because Hoshino possessed this charisma—the power to unite hearts and lead people to victory—that she had been able to overcome countless hardships and finally stand here.

"There will be no destruction, Marlene! Even the Leviathan—I'll never let it take away anything precious!"

Having regained her fighting spirit, Hoshino's crimson eyes shone with a light of hope that no despair could extinguish.

"Da Vinci-chan, you said earlier we 'made it in time.' That means you've figured out a way to break through this, right?!"

"But of course, Hoshino-chan! When it comes to thinking and research, leave it to the universal genius—me, Da Vinci!"

Da Vinci's proud voice overlapped with the rapid clacking of keys.

"Listen up, Hoshino-chan. Do you remember the Seal of Orichalcos?"

"I doubt I'll forget it in this lifetime."

That terrifying, cheat-like power of the Seal of Orichalcos had been the key to Dartz suppressing the world's top three duelists single-handedly.

"Actually, the Seal of Orichalcos originally came from Atlantis. It was their highest-grade ritual barrier, shrouded in mystery. You could say the Seal itself represented the pinnacle of Atlantean civilization. When it was corrupted by the power of the Orichalcos, it became the Triple Seal of Orichalcos that Dartz used."

Hoshino nodded in understanding. "So the Triple Seal had such terrifying power because it originated from that Atlantean seal?"

"Not quite. Rather than saying the Orichalcos was powerful because of that, it's more accurate to say its power was actually weakened by the Orichalcos's darkness."

"That… was weakened?!"

Hearing that, Hoshino Alter couldn't help but exclaim in shock: "So you're saying the original Atlantean seal was stronger than the Seal of Orichalcos?!"

As a field spell that combined healing, absolute resistance, and layered defense, the Seal of Orichalcos was already absurdly overpowered. The idea that its source was even stronger boggled the mind.

"According to ancient records, the Atlantean seal could only be used by the emperor. It was a last-resort trump card for when the nation faced annihilation, embodying the very peak of their civilization. Sadly, Dartz didn't use it to resist the Orichalcos—instead, he merged with its darkness."

"Okay, I get it—the seal's super strong. So Da Vinci-chan, please stop teasing and tell us the method already!"

Da Vinci's tone suddenly turned serious, and the sound of typing ceased.

"The original Atlantean seal—usable only by royalty—is now the only hope we have of defeating the Great Leviathan. A destiny intertwined for 10,000 years must be ended by Atlantis's own power. And Hoshino… you are the final heir to the Atlantean throne!"

[System Notice: Special Summon Shop Item has been Restocked.]

Following the system prompt, Hoshino opened the shop to see a single transparent card.

[Seal of Atlantis – Field Spell Card

Required Saint Quartz for Exchange: 0]

"This is the seal you were talking about, Da Vinci? It looks totally like a bootleg! And it's free?!"

As a certain famous internet entrepreneur once said: The most expensive things in life are 'free.' Coming from Da Vinci—a notorious profiteer—offering something for free was so suspicious Hoshino hesitated to even tap the button.

Then Holmes's voice interjected:

"That's because it's a replica. Ms. Da Vinci and I analyzed and recreated the Atlantean civilization's conceptual data to make this counterfeit. Just like the fake Millennium Item on your wrist, Hoshino-chan."

"Again… another fake…"

Using a counterfeit Millennium Item was one thing, but as the heir of Atlantis herself, having to use a fake version of her own nation's power—it was a little depressing.

Still, complaints aside, Hoshino dutifully tapped the exchange button. In a crisis like this, whether real or fake didn't matter—as long as it worked.

[Exchange Successful]

"Though we successfully replicated the concept of the Atlantean seal, how it functions and what effect it'll have depends entirely on you, Miss Hoshino. Even I can't predict what will happen in the next battle."

"We've done all we can. Whether the seal can defeat the Leviathan and sever the thousand-year grudge between Atlantis and the Orichalcos—it's all up to you now, Hoshino-chan!"

Sensing the last of her Command Seal's magical energy dwindling, Hoshino Alter urgently warned:

"Aibo! Nobu's Reality Marble seal is at its limit—it's breaking free!"

The serpent, empowered by both the god of Orichalcos and Zorc, lord of the underworld, must have some seriously divine attributes. Otherwise, Nobunaga's Sixth Heaven Demon King ability couldn't have restrained it longer than Iskandar's own army.

"ROOOOAAARRR—!"

A ground-shaking roar burst forth. The serpent's translucent, starlight-scaled body still burned with lingering flames—proof that even it had taken some heavy hits in Nobunaga's blazing hell.

"Aibo, we're out of time—now's the moment!"

"So this… this is the ultimate seal of Atlantis!"

As her fingers touched the card, a wave of awakening surged through her bloodline—pulling Hoshino's consciousness back to a vibrant, flourishing world 10,000 years ago.

A peaceful realm where humans lived in harmony with spirits, where ocean and sky melded on the horizon, reflecting the purity of human hearts at that time.

If only the Orichalcos had never corrupted it…

If only that meteor infused with Orichalcos energy had never fallen…

Atlantis might have thrived even now.

"But there's no such thing as 'if' in this world. Destruction was fated—but that grudge… I will sever it!"

At that moment, Hoshino's golden Duel Disk morphed into the familiar design of a modern-day one.

She opened the field spell zone on her Duel Disk and placed the card representing the ancient civilization's will.

"Feel the final will of Atlantis, Leviathan! In the name of the king, I activate the field spell—

First Seal: Atlantis of Miraculous Radiance!"