"Stealth Warriors", known as "The Warriors of Academia" in the Japanese version, is the fortieth episode of the Yu-Gi-Oh! ARC-V anime. It first aired in Japan on January 25, 2015 and in Australia on January 3, 2016. It became available with official subtitles via Crunchyroll on November 29, 2016.
During Zuzu and Gong's second-round Duels, Leo Institute of Dueling's Dipper is attacked by someone. Declan, who chased after the culprit that attacked Dipper, reaches a girl with an appearance similar to Zuzu's. At that time, the girl's servant begins a Duel with Declan. In order to confirm who the Zuzu-like girl is, Declan proceeds with the Duel...
Yuya declares battle, attacking "Idaten the Conqueror Star" with "Dark Rebellion Xyz Dragon's" "Mauling Mandible Charge", destroying it and abruptly reducing Iggy Arlo's LP to zero. In the darkened stadium, Nico Smiley shakily announces Yuya as the winner, Skip weakly congratulates Yuya, but the kids are terrified, since Yuya seemed like a different person. Yuya runs over to Iggy, offering him a hand up and asking if he's all right, but Iggy flinches and slaps Yuya's hand away. Looking up at Zuzu's nervous face, Yuya wonders what this feeling is.
In the observation room, Shay observes that Yuya has Yuto's card, and he heads off to meet him. Declan warns him not to impede on the progress of the tournament, reminding him not to forget why Declan is holding the tournament, but Shay scoffs and exits the room. Claude offers to have Shay put under surveillance, but their attention is caught by Nico, announcing that due to Dipper's absence, his second round match against Reed Pepper will go to Reed by default. Declan is surprised, and one of the technicians explains that around three hours ago, they detected a powerful Summoning energy in the city, a Fusion signature. He asks Declan to look at what the cameras they found recorded, and the screen shows the mysterious girl advancing on Dipper, who Claude recognizes. Holding up her Duel Disk, the girl causes a crimson light to emit from it, and when it fades, Dipper is gone. The girl picks up a card and waves it, then turns and leaves. Declan orders the tape to be rewound and enhanced, and upon seeing her face, which resembles Zuzu's, Claude gasps that it's Zuzu.
In the LID Center Court on the seventh day of the tournament, the results showing Olga's win against Haruno Mihara fade away as Nico announces the next match; You Show Duel School's Zuzu Boyle vs. Duel Girls Club's Micky Starlett. Zuzu enters the arena confidently, as her father, Gong and the kids cheer her on, while Yuya remains quiet and depressed. Zuzu waves to them, though she is discouraged by Yuya's expression. The crowd soon begin to cheer for Micky, who tells her fellow club members that now it's Duel Time, and to be sure to display their greatest self, and the greatest smile, putting their hands together and cheering, "Duel Girl's Club, Go!" Lights snap on as the members of the club skate into the arena, with Micky emerging last. Micky greets her fans, thanking them for coming today, and tells them that she'll Special Summon their hearts today. Zuzu looks around at the cheering crowd, having expected the Idol Duelist to effortlessly get her fans to cheer her on, but Zuzu is the poster girl of You Show Duel School, and will show them real Entertainment Dueling.
Meanwhile, Zuzu's Duel in the Second Stadium is being monitored by Declan's technicians, while the mysterious girl is in Paradise First Stadium. Declan muses that there's no mistaking her; that is definitely the girl from yesterday. Claude explains that the currently scheduled Senior match involves Kev Ravenwood, the previous Junior Youth champion, and Declan realizes that the girl's target is Kev. He get up from his chair, and explains that he's going to Paradise Stadium, warning them not to let Shay go there.
In Zuzu and Micky's Duel, Micky's "Gellenduo", powered up by two "Freya, Spirit of Victory", attacks and destroys "Canon the Melodious Diva", reducing Zuzu to 2900 LP. Nico comments that both Duelists are even in skill, and Micky agrees, but with the crowd's support, she has the strength of a hundred on her side. She waves to the crowd, telling them to enjoy every second of the Duel. Zuzu scoffs, remarking that she'll give everyone the best Duel that they can enjoy. Her father tells her to stay calm and burn on, as he'll transfer her the hot-blooded power of a hundred himself, while Gong explains that this man will cheer with the power of a hundred men. With the both of them, Zuzu will have the strength of two hundred, and the kids cheer, "Yay!" in the background. Yuya follows up with a half-hearted "yay..." and he looks at the "Dark Rebellion Xyz Dragon" card, recalling the attack on Iggy and wondering why it happened.
At the main stadium, the announcer explains that Kev Xyz Summoned "Hierophant of Prophecy", and used it to finish his match today. Kev himself enters a back area of the stadium, and he sees the mysterious girl and her companion walking towards him. He asks if she's the one who called him here, but the girl doesn't reply, ripping off her concealing overcoat and throwing out her arm in a challenge. kev seems intimidated, but Declan intervenes, explaining that he was the one who called Kev here. He apologizes to Kev and asks him to leave, congratulating Kev on a splendid Duel and telling Kev that he expects more from him in the future. Kev turns to leave and the mysterious girl protests, but Declan swiftly grabs her arm, adorned with a similar bracelet to Zuzu's, and he orders Kev to leave. Kev quickly flees, and the girl wrenches her arm free, telling Declan that if he's going to get in her way, then she'll take him out first. Her companion asks her to leave that to him, shedding his own overcoat. The girl tells Barrett to stay out of this, and Barrett replies that he cannot; the duty given to him by the Professor is to protect the girl from any sparks that may fall upon her. Scowling, the girl begins to walk away, but stops short when Declan asks if the Professor is Leo Akaba. Neither foe answers, Barrett strapping on a shield-like Duel Disk and activating its sword-shaped blade. Declan straps on his own Duel Disk, and orders the area to be sealed off, and not to let anyone in unless Declan tells them otherwise. He activates his Duel Disk, and the girl sits on the side.
Both Duelists yell, "DUEL!" and Barrett takes the first turn for the advantage, activating the Continuous Spell Card "Beastborg Fusioner", which allows him to Fusion Summon a "Beastborg" monster once per turn, as Declan expected. Barrett fuses "Panther Warrior" and "Dark Sentinel" and chants, "Ferocious black panther and guardian of sacred darkness, merge as one and let forth your valiant roar! Fusion Summon! Appear and come forth, Beastborg Panther Predator!" In the control room, the technicians detect a Summoning level that is almost equivalent to that the measurement recorded yesterday. Barrett activates the effect of "Panther Predator", inflicting half of its ATK to Declan, and "Panther Predator" blasts a red beam at Declan, who blocks the beam with his Duel Disk as his LP falls to 800. Barrett Sets two cards and ends his turn, the girl remarking that Barrett is already steadily wearing down his opponent's LP in a by-the-books strategy. Claude contacts Declan, confirming that Declan's opponents are Duelists from the Fusion Dimension. Declan replies that he knows.
Declaring his turn, Declan draws "D/D Lilith". He activates his own Continuous Spell Card, "Dark Contract with the Swamp King", which will inflict 1000 damage to him during his Standby Phase. Barrett is intrigued by the prospect of Declan damaging himself, and Declan explains that in exchange, once per turn, he is allowing to Fusion Summon a Fiend-TypeFusion Monster. He holds up the cards, declaring that he's fusing "D/D Cerberus" and "D/D Lilith". The mysterious girl reacts in shock at the sight of the "Cerberus" card, and Declan chants, "Hellhound that bares its fangs, vamp of the dark night! In whirlpool of light from the realm of the dead, become one and give birth to a new king. Fusion Summon! Be born! D/D/D Flame King Genghis!" He declares his Battle Phase and attacks "Panther Predator" with "Genghis", declaring "Fire Stroke". Flames envelop the greatsword of "Genghis and it slashes through "Panther Predator". Barrett falls to 3600 LP, but had already activated a Continuous Trap Card, "Beastborg Medal of the Shield", which gains a Medal Counter for every 100 Battle Damage that he took. Four medals materialize on the shield that appears, and Barrett adds that in addition, when "Panther Predator" is destroyed, he can Special Summon its Fusion Materials from his Graveyard. "Panther Warrior" and "Dark Sentinel" emerge from the Graveyard portal. Musing that Barrett had already planned for his monster's destruction, Declan ends his turn.
Adjusting his glasses, Declan comments that Barrett is unafraid of the risks needed to be taken for victory, and he seems to have an abundance of combat experience. Barrett is silent, remembering an incident in Heartland where he led three of his fellows into a "Widespread Ruin" trap, an incident implied to have caused the loss of his left eye. He then recalls meeting the mysterious girl in the corridors of Duel Academy, the girl having claimed that she would go to the Standard Dimension even if Barrett tried to stop her. Barrett replied that he would not stop the girl, but go with her, much to the girl's surprise, as all the other guards had tried to stop her (in the dub, Barrett also addresses her by name, the only time that the girl's name is spoken in this episode). Back in the present, Barrett thinks that he knew the risks, but if he is to return to the battlefield, he must produce sufficient results. He declares his turn and draws, then activates the effect of "Beastborg Fusioner" once again, fusing "Panther Warrior" and "Dark Sentinel". He tells "Panther Predator" to appear and come forth once more. Barrett then activates the other effect of "Beastborg Medal of the Shield", sending it to the Graveyard to increase the ATK of a "Beastborg" monster by 100 times the number of "Medal Counters" that "Shield" had. "Panther Predator" rises to 2000 ATK, much to the watching Claude's shock. Barrett activates another Continuous Trap Card, "Beastborg Medal of the Blade", which gains a "Medal Counter" for every 100 damage he deals to Declan. Declan observes that Barrett has quite a liking for war medals. Barrett replies that he is a warrior, and the number of medals he has is proof of his honor. Barrett activates the effect of "Panther Predator" to inflict half of its ATK to Declan, and this time, Declan takes 1000 damage, reducing him to 2200 as he blocks the beam again. "Medal of the Blade" gains ten "Medal Counters", and Barrett then sends "Medal of the Blade" to the Graveyard to activate its effect, increasing the ATK of a "Beastborg" monster he controls by 100 for each "Medal Counter" that "Medal of the Blade" had. "Panther Predator" rises to 3000 ATK, much to Claude's horror, and Barrett declares battle, attacking "Genghis" with "Panther Predator". "Panther Predator" severs one of the barbs of "Genghis" and snaps its sword with "Industrial Savage", reducing Declan to 1200 LP. Declan thinks that as he expected, Barrett has an abundance of combat experience. Setting a card, Barrett ends his turn, commenting that on his next turn, Declan will take 1000 damage due to his "Dark Contract with the Swamp King", correct? Declan confirms this.
With only the slightest hesitation, Declan draws, and he takes 1000 damage due to the effect of "Dark Contract with the Swamp King". He groans in pain as both the card and his heart glow purple, and he falls to 200 LP. Barrett declares that Declan has earned his respect, and Declan deserves a medal of honor as well. Declan retorts that he does not need such things, but this damage has sealed Barrett's fate. Barrett looks surprised as Declan steps forward, "D/D Savant Galilei" and "D/D Savant Kepler" reflected in his glasses. He uses the Scale 1 "Galilei" and the Scale 10 "Kepler" to Set the Pendulum Scale, allowing him to simultaneously Summon monsters from Levels2 to 9, and he chants, "Grand power that shakes my very soul, arise within me and give birth to a new light that renders the darkness. Pendulum Summon! Come before me, my monsters!" Two purple streaks appear from the Summoning portal as Declan calls, "Prideful knight, D/D Proud Chevalier! Vessel of disaster, D/D Pandora!" Barrett is shocked to see the Summon (in the dub it is more obvious that he is unfamiliar with the Summon), and Declan declares that there is still more, overlaying the Level 5 "Proud Chevalier" and "Pandora". He chants, "Hero of legends, pierce through all things with your profound justice! Xyz Summon! Descend, Rank 5, D/D/D Marksman King Tell!" The Pendulum-Xyz Summon shocks Barrett even more.
Declan activates the effect of "Tell." By using one Overlay Unit in a turn where he took damage from a "Dark Contract" card, he can reduce the ATK of one of Barrett's monsters by 1000 and inflicting 1000 damage to Barrett. Barrett realizes that this is why Declan took that damage. "Tell" absorbs one of its Overlay Units into its wrist-mounted crossbow and fires twin lightning arrows as Declan declares, "Electrostatic Arrow!", the first one hitting "Panther Predator" in the knee, reducing it to 2000 ATK, and the second exploding in front of Barrett, blasting him backwards and reducing him to 2600 LP. Barrett manages to push himself off the ground and flip upright. Declan uses the other Overlay Unit, and "Tell" fires its "Electrostatic Arrows" again, hitting "Panther Predator" in the chest, reducing it to 1000 ATK, and Barrett is hit in the shoulder. Barrett yanks the arrow out and crushes it as his LP falls to 1600. Declan tells them that he's not done yet, and he activates the second effect of "Dark Contract with the Swamp King"; he can banish Fusion Materials from his Graveyard to Fusion Summon a "D/D" Fusion Monster, much to Barrett's shock. Banishing "Proud Chevalier" and "Pandora", he chants, "Proud knight, be absorbed into the crucible of disaster! Be reborn into a new king! Fusion Summon! Come forth! Ruler who carries the glory of God! D/D/D Oracle King d'Arc!" Declaring his Battle Phase, Declan attacks with "d'Arc". Barrett refuses to fall that easily, and he activates a Trap Card, "Beastborg Medal of Honor." It destroys "Panther Predator" and Special Summons its Fusion Material Monsters from the Graveyard, then inflicts their total ATK to both players as damage. Power flows from the resurrected "Panther Warrior" and "Dark Sentinel", exploding above them as Barrett vows to take Declan out with him with the 3500 points of damage. Declan adjusts his glasses and tells Barrett that he won't let him, activating the effect of "d'Arc", negating the effect damage and gaining LP equal to the damage that was negated. "d'Arc" collects the energy in her claw with its "Life Elation" effect, and Declan gains 7000 LP, rising to 7200 LP. Barrett protests that it's impossible, and Declan orders "d'Arc" to resume battle with "Oracle Charge", destroying "Panther Warrior" and dropping Barrett's LP to 800. Declaring the finishing blow, Declan has "Tell" attack "Dark Sentinel" with "Forbidden Break Shot". "Tell" fires, and the arrow vanishes before it strikes, to "Barrett's" surprise. The attack hits home, and it blasts Barrett across the ground, reducing his LP to zero. The mysterious girl looks defiantly at Declan.
Mirroring her defiance, Zuzu has 100 LP to Micky's 1000, and only "Soprano the Melodious Songstress" on her field opposing Micky's "Wingweaver". Nico explains that it's been a truly heated match up until now, but Micky has taken the lead. With no cards in her hand, Zuzu prepares to draw, thinking that being able to enjoy situations like this is Entertainment Dueling. She draws dramatically, getting "Crystal Rose" and Summoning it. She uses its effect to treat it as "Mozarta the Melodious Maestra", and the light surrounding "Crystal Rose" refracts into an image of "Mozarta". Yuya looks around the stand as he sees everyone cheering Zuzu's move, remembering Yuto's final words. Zuzu uses the effect of "Soprano" to fuse "Crystal Rose" and "Soprano", chanting, "Angel's song! Supreme genius! With the guidance of the baton, gather your power! Fusion Summon! Now come here to the stage! Sing the song of victory! Bloom Diva the Melodious Choir!" Yuya muses "Give everyone smiles," and he wonders to himself what he's doing, reminding himself that this is Dueling. Zuzu attacks with "Bloom Diva", using her effect to prevent her destruction in battle and inflict the battle damage to Micky that Zuzu would have taken. "Bloom Diva's" "Reflect Shout" destroys "Wingweaver" and Micky is blasted backwards as her LP falls to zero. Nico declares that they have a winner, You Show Duel School's Zuzu Boyle, and that it truly was an amazing Duel. Zuzu winks at the crowd and looks up at Yuya, who laughs happily.
Back in the back area, the mysterious girl gets up and begins to walk off, but Declan tells Celina to wait, and Celina turns back to look at him (Declan does not address Celina by name in the dub, and instead claims that the tale that he tells will change her outlook forever).
Turn 3: Barrett
Barrett activates the effect of "Beastborg Fusioner", fusing "Panther Warrior" and "Dark Sentinel" from his field to Fusion Summon another "Beastborg Panther Predator" (1600/2000) in Attack Position. He activates the effect of "Medal of the Iron Shield", sending it to the Graveyard to have a face-up "Beastborg" monster he controls gain 100 ATK for each "Medal Counter" on it. Barrett chooses "Panther Predator" (1600 → 2000). Barrett activates his face-down "Beastborg Medal of the Blade". Once per turn, when he inflicts damage to Declan, Barrett can place a Medal Counter on it for every 100 damage. Barrett then activates the effect of "Panther Predator", inflicting damage to Declan equal to half of its current ATK (Declan: 3200 → 2200 LP, "Blade": 0 → 10 Medal Counters). Barrett activates the effect of "Blade", sending it to the Graveyard to have a "Beastborg" monster gain 100 ATK for each Medal Counter that was on "Medal of the Blade". He chooses "Panther Predator" ("Panther Predator": 2000 → 3000). "Panther Predator" attacks and destroys "Genghis" (Declan: 2200 → 1200 LP). Barrett Sets a card.
Turn 4: Declan
During his Standby Phase, the effect of "Dark Contract with the Swamp King" activates, inflicting 1000 damage to Declan (Declan: 1200 → 200 LP). Declan activates "D/D Savant Galilei" ( 1) and "D/D Savant Kepler" ( 10) in his Pendulum Zones. Declan Pendulum Summons "D/D Proud Chevalier" (2000/1700) and "D/D Pandora" (1700/2100) from his hand, both in Attack Position. He then overlays his two Level 5 monsters to Xyz Summon "D/D Marksman King Tell" (2300/2000). He activates its effect twice, detaching an Overlay Unit to reduce the ATK of a monster Barrett controls by 1000 and inflict 1000 damage to him ("Panther Predator": 3000 → 2000 → 1000, Barrett: 3600 → 2600 → 1600 LP). Declan then activates the effect of "Covenant with the Swamp King", which lets him banish monsters from his Graveyard if he would Fusion Summon a "D/D" monster. He activates the effect of "Covenant with the Swamp King", letting him Fusion Summon a Fiend-Type Fusion Monster. He banishes "Proud Chevalier" and "Pandora" from his Graveyard to Fusion Summon "D/D/D Oracle King d'Arc" (2800/2000) in Attack Position. "d'Arc" attacks "Panther Predator", but Barrett activates his face-down "Beastborg Medal of Honor" as a "Beastborg" Fusion Monster he controls is being targeted for an attack. He can destroy that Fusion Monster and Special Summon its Fusion Materials from theGraveyard, then inflict damage to both players equal to the combined ATK of the Summoned monsters. He destroys "Panther Predator" and Special Summons "Panther Warrior" (2000/1600) and "Dark Sentinel" (1500/1800), both in Attack Position, which would inflict 3500 damage to both players. As a player would take effect damage, Declan activates the effect of "d'Arc", making that damage 0 and increasing his LP by the same amount (Declan: 200 → 7200 LP). A replay occurs, and "d'Arc" attacks and destroys "Panther Warrior" (Barrett: 1600 → 800 LP). "Tell" attacks and destroys "Dark Sentinel" (Barrett: 800 → 0 LP).
The following cards appeared in this episode. Cards in italics debuted here.
In the dub, Declan says he's setting the Pendulum Scale with 1 and 11 but the monsters he shows and plays have Scales 1 and 10 respectively. In addition, he calls "Kepler" the Scale 1 monster and "Galilei" the Scale 11 monster; "Kepler" is a Scale 10 monster and "Galilei" a Scale 1 monster.