Sitting in his office is Seto Ossius. He's typing away at his terminal, performing some sort of work. In the background, the holonews is on. The news anchor says, "Today's big buzz is all about Duel Monsters. Earlier today, King of Games Yuni Oha," Seto turns around at the mention of Yuni, and watches more closely, "finalized his deal with notorious Schroeder Corp. He is now their official spokesperson." Seto's face shows disgust. "Most are shocked from this sudden devolvement, as it was generally assumed that Yuni would deny any such offers. The King of Games was unavailable for interviews, but did leave a statement saying that it was time for him to make some changes in his life. What was meant exactly by such a cryptic statement is still up to debate. More on this story as it develops."

Seto turns off the holovision and stands up. He presses a button on his comm system and says, "Cancel my appointments for the rest of the day. Something important has come up."

A voice replies, "Right away sir."

Seto reaches down to a cabinet and opens it, removing his Duel Gauntlet and deck. He slips it on. He says into the comm system, "Also, contact Schroeder Crop. Tell them that I wish to have a meeting with their new spokesperson here at Kaiba Corp. He'll know where to meet me."

Seto stands on one side of Kaiba Corp. Stadium, the same place were Yugi and Kaiba first dueled, as well as the location of Yuni and Seto's first duel. On the opposite side of the room, the doors open. Yuni walks in. He appears much worse than normal, as if he's permanently angry. Yuni looks around for a moment, and then demands, "I came because of the respect I have for you, but I am very busy. Why have you called me here?"

Seto smirks. "It would seem that you've finally grown a backbone. However, that's why I called you here. You aren't acting like yourself."

"And who are you to judge? You've made it your mission to associate with me as little as possible."

"Because you signed a contract with Schroeder Corp., and the Yuni I know would never do that. Now that I'm meeting with you face-to-face, I can tell that my assumption was correct. There's something wrong with you, and I'm staging an intervention." Seto holds up his arm with his Duel Gauntlet.

Now Yuni smirks. "You want to duel? Aren't you too busy for this nonsense?"

"I made time for this. Besides, I still need to get back at you for the World of Duel finals. Now, are we going to duel, or just stand here chatting?"

Yuni activates his Duel Gauntlet. "Fine, we will duel. I don't see what you plan to accomplish."

Seto activates his as well. The Duel Computer declares, "Duel now commencing. Seto Ossius vs. Yuni Oha. Scanning decks…decks accepted. Commence dueling."

Seto draws to take the first move and asks, "What, no catchphrase?"

Yuni scoffs, "I've changed. I don't need silly things like that anymore."

Seto proposes, "If you're so serious, then why don't we make this duel more serious? If I win, you quit your job at Schroeder Corp."

Yuni raises an eyebrow. "And if I win?"

"If you win, Kaiba Corp. will buy out your contract from Schroeder Corp. for double what they paid you."

"What's the matter Seto, are you jealous? Can't stand to see me working for your competition?"

"No, what I can't stand is you compromising your values by working for the likes of Schroeder. If it's about the money, Kaiba Corp. can offer more."

Yuni nods. "Fine, I'll accept those conditions, because I will win, just as I have before."

"Don't forget that I have beaten you before as well." Seto looks to his hand. "I activate Cosmic Signal! This card adds a level five or higher Comic or Plasma monster from my deck to my hand. I'll retrieve the Cosmic Neutron, and place it my Right Pendulum Zone (Right Pendulum Scale: 8)." To Seto's right, a large orb of black spatial energy appears in a column of light. "When I activate the Cosmic Neutron as a Spell Card, its effect activates, allowing me to add its partner from my deck to my hand." Seto searches his deck for a card. "Now in my Left Pendulum Zone I place Cosmic Orbiter (Left Pendulum Scale: 4)." On the other side of Seto, another column of light appears. This entity has the look of the fabric of space of Cosmic monsters, curled up into a ball. It moves as if orbiting around Seto's first Pendulum Monster. "Go, Pendulum Summon! I summon Plasma Star (Light/Level 5/Pyro/Effect/ATK 2100/DEF 0), Plasma Ghost (Light/Level 5/Fiend/Effect/ATK 0/DEF 2000), and Plasma Wall (Light/Level 6/Thunder/Effect/ATK 0/DEF 2500)!" Seto's three fearsome monsters made of Plasma appear before him. "When the Plasma Ghost is Special Summoned, I can draw a card." Seto does so. "And now that I've completed the Pendulum Summon, the effect of Cosmic Orbiter activates, increasing the levels of each summoned monster by one (Star and Ghost's Level: 6) (Wall's Level: 7)! Now I tribute all three monsters in order to summon Cosmic Mystic (Light/Level 7/Spellcaster/Effect/ATK ?/DEF ?)!" A large and imposing humanoid figure appears before Seto. It is cloaked in what looks like the night sky. "The Cosmic Mystic's power is drawn from the levels of the monsters I tribute to summon it, gaining 300 Attack and Defense Points for every level (ATK and DEF: 5700)! In case you can't tell, I don't plan on losing (Seto's hand: 2)."

Tori and Brutus march angrily into Schroeder Corp.'s lobby. They storm up to the front desk and Tori demands, "We need to see Yuni, now!"

The girl at the front desk looks up and says politely, "I'm sorry, but Mr. Oha is out at a business meeting right now. Would you like to leave a message for him?"

Brutus asks, "What do you mean by business meeting?"

"The President of Kaiba Corporation requested a face-to-face meeting him."

Tori and Brutus look at each other, both question, "Seto?" They immediately turn around and exit the building.

Yuni draws. "It's not as if I plan on losing either." He looks to his hand. "I summon the Cyber-Tech Falcon (Wind/Level 4/Winged-Beast/Effect/ATK 1500/DEF 1000)." Yuni's biomechanical falcon flies onto the field. "As I'm sure you remember from our first duel, the Falcon allows me to search for any Cyber-Tech card in my deck. I'll select the Cyber-Tech Flora, who can Special Summon itself if I tribute my Cyber-Tech Falcon (Earth/Level 6/Plant/Effect/ATK 1900/DEF 2400)." Yuni's monster appears to be a tree-like creature, augmented by cybernetic technology. "Now I Evolve it!" The newly summoned monster becomes cloaked in light as its shape begins to completely change, taking on a more humanoid form. "I Evolution Summon Cyber-Technomancer (Earth/Level 8/Spellcaster/Evolution/ATK 3000/DEF 2300)!" The glowing ceases, revealing the new monster. It is a cybernetic magician that appears to be more of an android than a cyborg. Various lights around its body blink on and off. "The Cyber-Technomancer can be Evolved from any level six or higher Cyber-Tech monster."

Seto comments, "As I know you are no fool, I would assume that your monster has an effect."

"And you would assume correctly. The effect of the Cyber-Technomancer can decrease the attack of one of your monsters by the same amount as the attack of the monster used as its Evolution Base. That means your Cosmic Mystic is losing 1900 points!" Yuni's monster creates a beam of black energy that fires at Seto's monster from its chest (ATK: 3800). "To further increase my capabilities, I activate Cyber Drain. This card destroys all other face up Spell Cards on the field and increases one of my Cyber monsters' attack by 500 for each one destroyed. Say good-bye to your Pendulum cards!" A pulse of electrical energy emanates from Yuni's monster and destroys both of Seto's Pendulum Monsters, sending them to the Extra Deck. The pulse then returns to the monster, strengthening it (ATK: 4000). "Cyber-Technomancer, attack and destroy the Cosmic Mystic!" Yuni's monster attacks using a similar beam from its chest as before, this time white in color. It destroys Seto's monster (Seto's LP: 3800). Yuni sets a card, and now that he has reached the end of his turn, Cyber-Technomancer Devolves back in to Cyber-Tech Flora. Yuni explains, "During the End Phase, Cyber-Tech Flora's effect allows it to change its battle position." The monster changes to a defensive posture (Yuni's hand: 3).

Seto draws, but as he does the doors to the arena suddenly open, and Brutus and Tori come running in. Seto comments, "Oh look, your cheerleaders have arrived. I thought something seemed off about you. Now I realize it was that they aren't with you."

Yuni looks at them disapprovingly. He claims, "I didn't want them here."

Tori shouts, "We have to talk to you Yuni!"

He replies with annoyance, "Can't you see I'm busy?"

Brutus shouts, "Please Yuni, something's not right. We need to talk!"

Yuni looks at them, when suddenly a look of shock crosses his face. Yugi's voice shouts, Brutus, Tori! There's a flash of light, and Brutus and Tori faint. Yuni quickly regains his composure.

Seto looks horrified and shocked. "What did you do!?"

Yuni looks at them, as calm and detached as ever. "I didn't do a thing. I'm not sure at all."

Seto begins to turn around. "I've got to get them medical attention."

Yuni commands, "Don't you dare move! If you leave your spot, you forfeit the duel."

Seto looks down to Tori and Brutus, and then back to Yuni. He thinks, I knew something was wrong with him, but I didn't think Yuni was insane! He has no care whatsoever for his friends. He looks at them again. They seem like they should be fine, at least for the remainder of the duel… Seto submits, "Fine. The duel will continue." He returns attention to the duel. "Using its effect, I'll summon the Plasma Serpent (Light/Level 5/Dragon/Effect/ATK 1800/DEF 2000). Now, by tributing it, I can Special Summon the Plasma Wyvern (Light/Level 7/Dragon/Effect/ATK 2600/DEF 2200)!" Seto's first monster appears on the field, only to burst into a flash of light, being replaced by the wyvern. "Plasma Wyvern, destroy Cyber-Tech Flora!" Seto's monster breathes a plasma breath, burning away Yuni's monster. Seto sets the last card in his hand. "I end my turn (Seto's hand: 0)."

Tori and Brutus slowly wake up. They look groggy and confused. They both struggle to stand up. They look around. It is immediately obvious that they are no longer at Kaiba Corp. Arena. They seem to be standing in the courtyard of some ruins. Upon further investigation, they seem to be in the Realm of Chaos. Tori is the first to ask the obvious. "Where are we?"

Brutus is just as baffled. "I don't know." He looks up to an energy current in the sky above them. "All I know is that I've never seen anything like that before. What happened?"

Tori thinks back. "We were confronting Yuni, when suddenly I heard a voice…it had to be Yugi's voice!"

Brutus nods. "Yeah…I heard it too."

That's when Yugi's voice says aloud, "Sorry about that guys."

Tori and Brutus turn around quickly. Behind them, in the flesh, is Yugi. Tori exclaims, "Yugi! I can't believe I'm actually seeing you in person!" After getting over her moment of geeking out, Tori recomposes herself and asks, "What's going on here?"

Yugi responds, "Too much to explain right now. I'll have to tell you on the way."

Brutus asks, "On the way where?"

"On the way to save Yuni."

Seto looks at Yuni and thinks, Yuni is just too off right now. There's no way this is the same person I dueled almost a year ago. Something is very wrong here.

Yuni draws. He looks over to the bodies of his friends, which still lie unconscious behind him. After a split moment, he looks back, seeming to no longer care. "Since you control your Plasma Wyvern, and I control no monsters, I can Special Summon the Cyber-Tech Accelerator (Wind/Level 5/Machine/Effect/ATK 2000/DEF 2000). To add to my forces, I can Normal Summon the Cyber-Tech Berserker (Dark/Level 5/Fiend/Effect/ATK 2300/DEF 1100) with its effect. Now I use my two level five monsters in order to build the Overlay Network! I Xyz Summon Cyber-Tech Starship (Light/Rank 5/Machine/Xyz/ATK 2500/DEF 2400) (OVL: 2)!" From the portal of the Overlay Network, Yuni's space-faring monster emerges. "Now by removing one Overlay Unit, my Cyber-Tech Starship can decrease the attack of your monster by 300, while also increasing its own by the same amount (OVL: 1) (Wyvern's ATK: 2300) (Starship's ATK: 2800). Go Cyber-Tech Starship, strafe Seto's Plasma Wyvern!" The monster attacks with a laser-based weapon.

Seto counters, "Activate Trap Card: Plasma Flare! This card destroys any monster that dares attempt an attack against a Plasma monster!" A burst of plasma flies out of Plasma Wyvern and shatters Yuni's monster. Seto suddenly taunts, "Yuni, something is wrong with you! If I know any two things about you, it's that you care about your friends more than anything, and that you would never mess up this badly when dueling! I'm calling you out! Who are you, and what have you done with Yuni!?"

Yuni begins to chuckle, lightly at first, but it soon turns into a full out evil laugh. His eyes turn purple and a dark aura surrounds him. He declares in a malevolent voice, "How observant of you Seto! I am not the Yuni you used to know! That weakling is gone for good!"

Seto is shocked. He demands, "What is going on here!?"

"More than you could understand. You are wrong on one point though: my dueling is better than ever before! I activate my trap, Cyber-Tech Foundry! This card Special Summons a Cyber-Tech monster straight from my hand! I summon Cyber-Tech Corruption (Dark/Level 8/Fiend/Effect/ATK 2900/DEF 2000)!" A dark creature, seemingly made of shadows, appears on Yuni's field. Despite its non-solid appearance, it somehow is covered by cybernetic armor. "Cyber-Tech Corruption, let's do this for real this time! Attack the Plasma Wyvern!"

Seto counters, "By banishing a Plasma monster from my grave, I can negate my Wyvern's destruction!

Yuni returns, "Then it's too bad for you that you can't activate monster effects when Plasma Corruption declares an attack!" A stream of shadows comes from Yuni's monster and wraps around Seto's, destroying it (Seto's LP: 3200). Suddenly, a dark and corrupted version of the Plasma Wyvern appears on Yuni's field.

Seto demands, "What just happened!?"

"Cyber-Tech Corruption has the ability to corrupt any monster it destroys, summoning it to my side of the field. Your monster serves me now (Yuni's hand: 1)!" Yuni laughs again.

Yugi, Tori, and Brutus trek through the ruins. Brutus asks, "So where are we exactly?"

Yugi responds, "That really depends on what you define as here. Technically, your bodies are still in Seto's arena. The area that it looks like we're in is the Realm of Chaos. The specific answer would be Yuni's mind."

Brutus and Tori ask, "Yuni's mind?"

Yugi nods. "Yes, that's why you can see me. As for why you're here, it's because I needed your help. A year ago, when Yuni succumbed to the Darkness, I was forced into this exact same area of Yuni's mind. I was cut off from all interaction with him. It's now happening again."

Tori asks with surprise, "Yuni's been taken over by the Darkness again?!"

Yugi nods. "Except it's different this time. Last time Yuni succumbed to his own dark emotions. It's something more this time. There's some sort of external influence."

Now Brutus asks, "So Yuni's been possessed?"

"I'm not sure that that's the word I would use, but something along those lines. I needed your help because I wasn't able to penetrate deep enough into these ruins alone. I encountered resistance about…" He suddenly shouts, "Here! Look out!"

The three of them jump out of the way as an attack is launched at them by a nearby Cyber-Tech Corruption. The three prepare for action. A Duel Disk appears on Yugi's wrist, while a Duel Gauntlet appears on Brutus' and Tori's. Yugi pulls out a card. "I summon the Black Luster Soldier!" The Black Luster Soldier slashes its sword at the opposing monster, destroying it. Yugi shouts, "Come on, we have to hurry now!" They begin to run.

Another two Cyber-Tech Corruptions appear. Tori and Brutus both pull out a card. Brutus shouts, "Come on Brutal Massive Dragon!"

Tori declares, "Fight for me Megalithic Pyramidal!" The two monsters appear and launch their respective attacks against the pursuing monsters, destroying them both.

Once they're gone, Yugi explains, "This was as far as I was able to get on my own before I was overwhelmed. I wasn't able to fight all three alone. I have no idea what's beyond this point. I must warn you that if something happens to you here, there's no knowing what could happen to your body. If you two want to leave, Yuni and I won't hold it against you."

Tori shakes her head. "No way, we're not going anywhere."

Brutus adds, "Yeah, we're ready to do whatever we have to do to rescue Yuni."

Yugi nods. "Thanks guys." He turns around. "We shouldn't be too far from the center of the temple complex, which should be our goal." They continue hurrying on.

Around a bend, they encounter a large group of various Cyber-Tech monsters, including Cyber-Tech Flora, Cyber-Tech Falcon, and Cyber-Technomancer. Yugi pulls out another card. "Dark Magician, I need your help!" Yugi's famous magician appears before him. "Dark Magician, attack with Dark Magic Attack! Black Luster Soldier, Chaos Blade!"

Brutus adds, "Brutal Massive Dragon, use your Brutanic Bombardment!"

Tori finishes, "Megalithic Pyramidal, Pyramidal Slash!" The four monsters go into combat with the horde of monsters, attacking each one. There is some resistance, but the Cyber-Tech monsters are destroyed.

Yugi points to a large door to a building. "That's it, the central hub!" They run in.

Inside is a large room decorated with hieroglyphs of Chaos. In the center is a figure. Brutus recognizes the figure. He runs towards it shouting, "Yuni!"

The figure turns around, stepping into the light. It's not Yuni. It appears like it could be Prince Yu-Gi-Oh of Yugoha, but it quickly becomes evident that it's not. His hair is just purple and black, his skin is pale, and a dark aura surrounds him.

Brutus staggers and steps back. "Who…who are you?"

The person responds, "I don't have a name."

Tori observes, "You look like Prince Yu-Gi-Oh, is that who you are?"

He laughs. "Ha! Prince Yu-Gi-Oh was a weakling who couldn't bring himself to finish me off properly. Because of his blunder, I have returned. I am his better half, his dark half! The yin to his yang! Now just as he was revived in the form of Yuni, I too have been! I suppose you may call me Yami Yu-Gi-Oh."

Yugi demands, "What have you done with Yuni!?"

"The one you seek is over there." He points to the far corner of the room. Yuni sits huddled in a fetal position there.

Yugi approaches him. He asks, "Yuni…can you hear me…?"

Yuni rocks back and forth. He whispers to himself, "Can't…let…Darkness…take…hold…"

Yami Yu-Gi-Oh comments, "He really is quite pathetic. It is his fear of the Darkness that allowed me to take hold over him."

Tori shouts, "Yuni, you've got to snap out of it! You're allowing the Darkness to control you again!"

Brutus adds, "Come on, you need to fight back!"

Yami Yu-Gi-Oh claims, "It really won't do you any good, he's stuck like that for good. This body is mine now." He laughs. "I really must admit, I thought I'd be stuck in that wretched meteorite prison for an eternity. I had no idea that Yu-Gi-Oh had actually managed to survive this long, providing a suitable replacement body for me."

Brutus leaps at him shouting, "You monster!"

Yami Yu-Gi-Oh flicks his wrist, sending Brutus flying backwards. He says, "This body is mine now, I have control in here. Now I suggest you get out of here while I'm still in good mood."

Yugi looks angrily at him. "Never."

Yami Yu-Gi-Oh snaps his fingers, and suddenly another horde of Cyber-Tech monsters appears before them. They slowly approach Yugi, Brutus, and Tori. Yugi starts to say, "Dark Magician, Dark Magic-" He's cut off when the Cyber-Tech monsters destroy all four of their monsters. They are surrounded with no way of fighting back. Yami Yu-Gi-Oh laughs. "So long!"

Yugi shouts, "Yuni, you have to help us! We need you! This is your mind, you stop this! Help!"

Yami Yu-Gi-Oh shouts, "There's no one that can save you now! Attack, my monsters!"

The leading Cyber-Tech Corruption launches a stream of shadows at them. Just as it's about to hit them, it suddenly disappears. Then all of the monsters disappear.

Yami Yu-Gi-Oh shouts in disbelief, "What happened!?"

Yuni responds, "This is my mind, and I'm taking control!"

Despite Yuni's reappearance, he still appears twisted and dark on the outside. He states, "You're right Seto, I am different. I will never be the same, pathetic, weakling you used to know."

Seto retorts, "I may have once called you a pathetic weakling myself, but I assure you that what you were was far superior to what you've become." He draws. "I activate the Pot of Greed!" Seto draws two cards. "Now I activate Dimensional Shift!" Space-time around the duel arena seems to distort. The twisting makes it appear as if Yuni's monsters are on Seto's side of the field. Seto explains, "Since I control no monsters, I can pay 1000 of my life points in order to use your monsters as a tribute for one of my effects (Seto's LP: 2200). That includes for the tribute of my ultimate monster! I tribute your two monsters in order to summon the Cosmic Plasma Dragon (Light/Level 8/Dragon/Effect/ATK 3000/DEF 2500)!" Emerging from its star, Seto's dragon of white plasma appears on the field. "Fortunately for you, I can't declare attacks the turn I use Dimensional Shift. I end my turn (Seto's hand: 0)."

Yugi, Tori, and Brutus look towards Yuni with surprise. Yami Yu-Gi-Oh looks at him with shock as well. He demands, "You are defenseless! How did you manage to gain control!?"

Yuni replies, "The only thing I fear more than being taken by the Darkness is losing my friends. I won't let you harm them."

"I allowed you to remain here because I saw no reason to destroy you. I can see that has changed now." From his hand, Yami Yu-Gi-Oh launches an orb of dark energy.

Yuni snaps his fingers and the attack disappears. "This is my mind. I rule here." Yuni then counterattacks with an orb of light energy.

In a similar fashion to Yuni, Yami Yu-Gi-Oh snaps his fingers, and halts Yuni's assault. He observes, "It would seem that this will lead to a standstill."

Yuni nods in agreement. "There's only one way to solve this." He holds up his arm and a Duel Gauntlet appears on it.

Yami Yu-Gi-Oh does likewise. Before starting, he says, "Just know that I won't be alone." He points to some sort of cylindrical container in the center of the room. The container suddenly breaks. Yuni looks at the scene with horror. Out of the broken cylinder, a purple mist floats towards Yami Yu-Gi-Oh.

Brutus asks, "What is that Yuni?"

Yuni responds morbidly, "That's where I locked away my dark emotions…it's my dark half."

As he says this, the purple mist takes solid form, it becomes Yuni as he was when the Darkness took over. Yami Yu-Gi-Oh proclaims, "I am the dark half of Yu-Gi-Oh, and this is the dark half of you, reincarnation of Yu-Gi-Oh! We are one and the same!" The two bodies turn into the same purple mist as before, and the two forms of mist merge into one, taking shape once more. The new form has the physical shape of Yuni, but the hair coloration, skin color, and aura of Yami Yu-Gi-Oh. He declares, "I am now Yami Yuni, your worst nightmare incarnate." He laughs.

A dark mist enshrouds Yuni. He laughs identically to the way Yami Yuni just did. Seto demands, "What's going on here!?"

Yuni's voice, now twisted by darkness and overlaid with a demonic voice, answers, "It's time for my outward appearance to mirror my inner!" The mist clears, revealing Yami Yuni.

"What happened to you!?"

Yami Yuni chuckles. "This is my true form! Darkness is an undeniable truth of the universe, and this is me when I embrace it!"

Seto thinks, I've only seen Yuni like this once before…He recalls Yuni's duel with Oblivion. He never explained fully what happened, but he seemed to be possessed by some sort of darkness, just like I was after my duel with Scourge. It must be happening again! That's what's wrong with him! He almost sighs. I hate this mystical magic stuff…

Yami Yuni draws. "It would appear that you have backed me into a corner, and I must take the defensive for this turn. I'll just set this monster. But trust me, I'll come back stronger than before, next turn (Yami Yuni's hand: 1)."