Heroic Spirit Deck in Yu-Gi-Oh!

"Two souls sharing one body? What are you talking about, Mr. Holmes?"

The sudden revelation left Mash's mind in disarray, making it difficult for her to grasp what 'Holmes' had just implied.

Okita interrupted, "Forget about the complicated stuff for now! Isn't Master about to lose?"

Emiya waved his hand dismissively. "No, no, no! More than the duel's outcome, what Holmes just said is the real issue here!"

On the field, Moriarty's coffin-like cannon was aimed directly at Hoshino's neck, pressing against her skin through the now-empty battlefield.

"Miss Hoshino, as per our agreement, if I win this duel, you must reveal everything you know—without exception."

Hoshino swallowed hard, feeling the weight of impending defeat. "Holmes… and Moriarty? When did you notice?"

Since Da Vinci had gone to such lengths to conceal this experiment—testing the coexistence of two souls in one body—Chaldea must have been aware of it even before the duel began.

"Monitoring Master's physical condition is one of our duties. Do you really think something this significant would go unnoticed?"

Mash's eyes widened in surprise. "So Mr. Holmes, you already knew something was happening? Then… back when I went to wake you up, was that reluctance to get out of bed just an act?"

"No, that was real. I've been staying up way too late these past few nights."

Holmes answered honestly, then turned his gaze toward Hoshino, pressing her for an answer.

"Now it's your turn to answer! Don't think we'll go easy on you just because you look like Miss Hoshino!"

Faced with Holmes' interrogation and Moriarty's gun barrel at her throat, Hoshino shrugged helplessly.

"If I insist that I really am Hoshino Chiyuki, are you going to torture me for a confession? Besides, Holmes, don't you think you're being a little too hasty…?"

"What?!"

At that moment, the black mud beneath their feet, which had previously settled, began to stir and surge in an unprecedented frenzy.

"What makes you so sure you've already won? Holmes, Moriarty—until the final trigger is pulled, victory is never certain!"

Artoria was visibly shaken. The disturbing sensation underfoot forced her to acknowledge reality.

"This… this substance is starting to manifest physically! It's no longer just a hologram—it's invading reality!"

Holmes' expression darkened. "Impossible! How can the Field Spell still be activated when there are no monsters or set cards in play?! No more delays—Moriarty, attack directly!"

—Bang!

The gunshot rang out, but the attack did not pierce Hoshino as expected. Instead, sparks scattered upon striking a black blade.

"Even without monsters or set cards, I still have my field and my last remaining hand card! I activate the monster effect of [Heroic Spirit – Saint George Alter] from my hand!"

Clad in black dragon armor, George Alter planted his feet firmly into the black mud, his longsword intercepting Moriarty's decisive strike.

"When the Field Spell [All the Evils of This World] is active, I can Special Summon George Alter from my hand when my opponent declares a direct attack!"

Hoshino flipped the card in her hand and placed it onto the field.

"I'm counting on you this time, George. I swear I won't let you die again!"

[Heroic Spirit – Saint George Alter★★★★★★★★ (Level 8)][DARK][Dragon/Effect][ATK 2000/DEF 3000]

Holmes' shock was evident. "Impossible! George shouldn't have an Alter form!"

The corrupted Saint George gazed upon them with cold, abyssal eyes, his sword glowing with the power of destruction.

"Behold the truth of the Ascalon tainted by sin! You are all but evil dragons before me—The Absolute Sword of Annihilation!"

The black blade swept across the battlefield, scattering black mud and severing Holmes' field in a single, decisive stroke.

"When George Alter is successfully Special Summoned, he destroys all monsters on the opponent's field! This card's attack power increases by 1000 for each monster destroyed!"

[Heroic Spirit – James Moriarty DESTROYED]

[Saint George Alter ATK 2000 → 3000]

Okita clenched her fists in excitement. "Amazing! That was an incredible strike!"

Mash, still in disbelief, whispered, "George… was always so kind. He would sacrifice himself time and again to protect Master. I never imagined he had this kind of form…"

The battlefield had shifted. Hoshino smirked at her opponent.

"What's wrong, Holmes? The victory you spoke of never arrived. Which means—I don't have to tell you anything. Oh, wait! Given your intellect, you must have realized something by now, haven't you?"

Holmes' expression grew increasingly grim. "This… this isn't right. It's not just the impossible concept of a Saint's Alter form—there's no record of this version of Saint George in Chaldea's Spirit Origin database!"

He had suspected something when he checked her deck earlier but had been unable to pinpoint the anomaly. Now, there was no need for Hoshino to hide it anymore.

"Let's keep dueling, Holmes. Moriarty. This duel isn't over yet!"

Holmes narrowed his eyes, drawing his last remaining card.

"I activate the Quick-Play Spell [Heroic Spirit—Emergency Summoning]! This lets me Special Summon the [Heroic Spirit – Sherlock Holmes] I shuffled back into my deck last turn, in Defense Position. Turn end!"

Holmes, now without offensive options, could only defend. But even if his defense was weak, there was still one glimmer of hope—Hoshino's top-decked card was the Vessel of the Saint he had returned earlier, meaning she had no immediate way to summon another monster for a decisive blow.

"You're just betting that I can't summon a second monster this turn, huh? Well then—my turn! Draw!"

Hoshino pulled the very card Holmes had placed atop her deck, then curved her lips into a mischievous smile.

"Hey, Holmes, Moriarty—want to see something interesting? Something you've never seen before?"

She discarded the drawn card without hesitation. At the same time, George Alter plunged his sword deep into the black mud.

"George Alter's effect activates! Once per turn, I can discard one card to add a Dragon-type monster from my Graveyard to my hand! I'm retrieving Artoria Pendragon Alter!"

As soon as the card reached her hand, the black mud beneath them trembled violently.

"Next, I activate my Field Spell All the Evils of This World! By banishing Artoria Pendragon Alter from my hand, I can add [Heroic Spirit – Gilgamesh Alter] to my hand!"

Hoshino raised her newly acquired card.

"This duel is mine! Perish beneath the roars of the sword that rends the very sky!"

In the void, the accumulated black mud energy condensed into a tangible form. A Heroic Spirit, molded from an unfathomable amount of the world's evils, stepped onto the tainted ground.

"—I banish Gilgamesh from my Graveyard to Special Summon [Heroic Spirit – Gilgamesh Alter] from my hand!"

[Heroic Spirit – Gilgamesh Alter★★★★★★★★★★ (Level 10)][DARK][Warrior/Effect][ATK ?/DEF?]

[Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by banishing 1 "Heroic Spirit – King of Heroes Gilgamesh" from your GY.]

Gilgamesh Alter stood before them. Though his usual arrogance remained, a new, unreadable sinister smile played upon his lips.

"Gilgamesh Alter's special effect—when Special Summoned, he equips as many Equip Spells from my Deck as possible, negating their effects. Each equipped card increases his ATK by 1000!"

[Gilgamesh Alter ATK 5000]

Outmaneuvering Holmes' calculations, Hoshino had successfully summoned a monster, shattering his last line of defense.

"It's over, Holmes! Moriarty! Attack, George, Gilgamesh! Witness the countdown to this era's end!"

A blade and a Noble Phantasm cut through the air, obliterating Holmes' defending monster and piercing through his frail body.

[Holmes' LP: 700 → 0]

[Duel Over. Winner: Hoshino Chiyuki!]

"This is truly troublesome—a Heroic Spirit Alter unrecorded in the database, along with an evil force capable of corrupting both a Saint and the King of Heroes. It seems the situation is far worse than Ms. Da Vinci predicted."

Hoshino grinned mischievously at Holmes. "Hehe, I win. So, as per our agreement, I'll be taking your Deck now~"

Feeling the black mud constricting even tighter around his feet, Holmes forced out a small smile. "Heh… Miss Hoshino, I doubt what you truly want is just my Deck, isn't it?"

"Holmes, are you okay?" Mash's voice carried a hint of panic as she noticed Holmes' strained expression. More concerningly, even after the duel had ended, the black mud and the Altered Heroic Spirits showed no signs of dissipating.

Hoshino licked her lips seductively. "As expected of you, Holmes. You see right through me—I don't just want your Deck. I want you as well~"

"Miss Hoshino, under normal circumstances, I might find that quite flattering. But in this situation, I'm afraid I must refuse!"

Holmes firmly rejected her, then quickly turned to Mash. "Miss Mash, report the situation to Ms. Da Vinci immediately! Emiya, Okita, Artoria—cover the retreat!"

Swinging his cane to break free from the black mud's grip, Holmes managed to regain some mobility.

"Understood, Mr. Holmes!"

Boom—!

Just as Mash attempted to activate the door's unlocking mechanism, a black Noble Phantasm shot through the air, striking the control panel and triggering an explosion.

"Oh my dear kouhai~ Leaving already? Come play with your senpai a little longer~"

Under Hoshino's command, the corrupted Gate of Babylon rained down its darkened treasures, blocking Mash's escape route.

"Step aside, Mash! I'll clear the way!"

Artoria materialized Excalibur in her hands, unleashing a full-powered slash imbued with Magic Burst. The black Noble Phantasms, along with the Chaldea cafeteria door, were obliterated in a single strike.

Standing ready for battle, Emiya projected Kanshou and Bakuya, intercepting the follow-up barrage from the corrupted Gate of Babylon midair. "So we're fighting now, huh? Tell me, Alter King of Heroes, do you have enough treasures stocked up?"

Unlike Emiya and Artoria, who had instantly adapted to battle, Okita—still unfamiliar with the black mud—was visibly confused. "Wait, wait, wait! Why is everyone suddenly acting like this is a life-or-death fight? Didn't the duel just end?"

A black sword light flashed. Without hesitation, George Alter swung his blade at Okita. Yet even in her confusion, Okita's instincts as a genius swordswoman allowed her to evade the attack just in time. In the same motion, she drew her blade from her waist.

"Oh? So we're really doing this? Well then, let's have a little match, shall we, George Alter?"

Hoshino watched the scene unfold with amusement, her lips slightly parted. As she glanced toward Mash—who had already escaped under the cover of Emiya, Okita, and Artoria—she sighed dramatically.

"Ah, truly impressive. You people of Chaldea are as battle-hardened as expected—adapting so quickly to the situation."

Holmes, gripping his cane tightly, warned her sternly, "Miss Hoshino, don't forget where you are—this is Chaldea. If you continue this madness, Master or not, you will be severely punished!"

Hoshino smirked, making no attempt to hide the sinister delight in her expression. "This isn't just madness, Holmes. No one knows Chaldea's combat strength better than I do. However…"

Casually, she drew two cards from her deck and tossed them into the black mud beneath her feet. "If it's raw battle power you're talking about—I've already perfectly outmatched you all."

The black mud greedily absorbed the cards, surging with even greater energy as two new dark silhouettes emerged from its depths.

"—Come forth, Karna Alter, Ozymandias Alter!!"

(*****)

If you'd like to read 25 chapters ahead, please consider joining my Patreon: patreon.com/ANeet. Your support means a lot. Thank you!