That night, a trail of golden particles slipped out from a dorm room in the Slifer Red Dorm and drifted quietly into the darkness, moving through the treelines before heading deeper into the forest and back toward the ruined remains of Professor Viper's facility.
Not long after, Yubel began to materialize once again, though this time only part of her appeared at first, taking the form of an entire arm as her presence slowly gathered itself together.
"Damn it..." she muttered through gritted teeth, her voice carrying a hint of exhaustion. "I almost exposed myself..."
After Yumi had defeated her, the remaining fragments of her consciousness had been forced to shift toward the power she had placed inside Viper. In order to recover whatever she could, she had then intensified the flow of Spirit Energy draining from both Viper and Jaden, pushing the system harder than before and gathering as much strength as possible before her condition worsened further.
It wasn't nearly enough to restore her.
Still, it had allowed her consciousness to survive.
Afterward, she hid herself inside Viper's corpse, suppressing her presence completely while waiting for someone to approach.
The moment Celina came close enough to confirm Viper's death, Yubel quietly attached herself to the girl without anyone noticing.
Using Celina's body as a temporary host, she carefully siphoned Spirit Energy from Yumi throughout the night.
The amount she managed to collect from him was greater than everything she had gathered over the entire past week.
Just remembering it made her body tremble.
"...Is he even human?" Her voice echoed through the empty ruins. "Who the hell keeps going for thirty whole minutes without slowing down even once!?"
She clenched her claw into a fist.
"And why the hell are his techniques so good!?"
Her face immediately twisted with jealousy.
"That damn homewrecker..." She ground her teeth together. "She has to be the reason! She must've been doing all of this with my Jaden while I wasn't around!"
The more she thought about it... The angrier she became.
She had tried to endure.
She really had.
At first, she planned to remain hidden inside Celina until she had absorbed enough Spirit Energy to restore her entire body.
But as time went on... Yumi and Celina grew more and more energetic.
While the Spirit Energy pouring into Celina and taken by Yubel continued increasing at an almost ridiculous rate.
Ordinarily, that should have made her happy. Instead, watching everything through Celina's senses had nearly driven her insane.
Every second felt like torture.
Every passing minute made the jealousy inside her grow stronger.
Eventually, she simply couldn't take it anymore.
Fearing that she would completely lose control of herself, Yubel separated from Celina and fled before anyone noticed her existence.
If she could have gone for a full-body possession, then she might not mind, but she couldn't. Doing so meant exposing herself, so she stayed hidden inside Celina while letting her take the full forces of his attacks.
Even after escaping... She could still remember everything she had witnessed.
"Unforgivable..." She hugged herself tightly. "Absolutely unforgivable..."
After standing there silently for several moments, the anger slowly faded, replaced by uncertainty.
"There are..." She lowered her head. "Two Jadens..."
Her voice became noticeably quieter.
"If this Jaden betrayed me..." She hesitated before forcing herself to continue. "Then surely... the other one won't... right?"
The problem was that the two of them shared far too many familiar traits.
That was what made her so confused.
Both of them had the power to command and create Duel Spirits. Both of them carried a deep bond with those spirits. Both of them were strong, and both of them were protective toward the people close to them. No matter how she looked at it, they were far too similar in the ways that mattered most to her, which was exactly why she had ended up treating Yumi not as Yumi, but simply as Jaden No. 2.
As confusion, jealousy, and resentment slowly mixed together inside her heart, the darkness surrounding the ruined facility suddenly became noticeably heavier.
A dark voice suddenly echoed in her mind.
"You want revenge, don't you?"
Yubel snapped out of her thoughts at once.
"Who's there!?"
Her body tensed immediately as she looked around, alarmed by the unfamiliar presence now pressing against her senses. Then, from the shadows before her, a dark figure slowly emerged, taking on a somewhat transparent spiritual form that resembled a massive black lobster with a skull-like face.
"You can call me Tragoedia," the spirit said calmly.
Yubel instinctively took a step back. "What do you want?"
Darkness seemed to leak from the spirit's body, and that alone was enough to make her wary.
Rather than answering her question, Tragoedia simply chuckled.
"You wish to reunite with your beloved Jaden, do you not?"
Yubel froze. "I..."
"There is a way for you to accomplish your goal and be forever reunited with your beloved Jaden Yuki," Tragoedia continued, his voice growing more persuasive with each word, like some devil trying to tempt her into making a deal she would regret. "You simply need power. Power that can shatter the barrier between dimensions and bring spirits and humans together."
Yubel listened in silence.
"I can grant you that power," Tragoedia said. "All you need to do is retrieve the final Planet Card, The Tyrant Neptune, from Yumi Uzushi. Retrieve it for me and the path toward your eternal reunion with Jaden will finally become reality."
Yubel did not respond right away.
After years of dealing with malicious spirits alongside the Supreme King, she knew a trap when she saw one. Tragoedia clearly intended to use her for something, and there was no reason to believe he was offering this power out of kindness. He would probably treat her like nothing more than a tool once she had served her purpose.
And yet...
Thinking back on what she saw as Jaden No. 2's betrayal, and the growing bitterness that had been building inside her ever since.
Her claw slowly tightened.
"If... If this is what it takes..." She whispered.
Slowly, she reached her hand toward Tragoedia.
"Then I'll accept."
The spirit's smile quietly grew wider.
...
The next morning, sunlight filtered weakly through the dusty window of the Slifer Red dorm, painting a warm stripe across the tangled sheets.
Celina stirred with a soft groan, the events of the previous evening settling over her like a heavy, confusing blanket.
"Uhhh…" she yawned, pushing herself up on her elbows.
She blinked slowly, the room coming into focus: the familiar, worn-out furniture, the scattered clothes on the floor, and the boy sleeping soundly beside her. Her long indigo hair fell in a messy cascade over her bare shoulders. Under the single shared blanket, she was acutely aware of their nakedness, a physical reminder of a line they both crossed last night.
Why did I even do that? she thought.
The question echoed in her sleep-fogged mind as she rubbed her temples. It wasn't like her. Sure, she'd had feelings for Yumi for a while, a confusing, frustrating jumble of affection and competitive fire, but she hadn't even worked up the courage to ask him to be her boyfriend.
So what had possessed her last night to slip from her own bed, cross the quiet space between them, and… initiate everything?
A flush of heat crept up her neck as the memories replayed. The initial boldness, the way the tension had melted, and then… the sheer, unbelievable endurance. A fresh wave of embarrassment washed over her.
Is he even human? she wondered, a little indignantly.
How could anyone stay that… energetic… for an entire night? It defied all logic. He'd only finally slowed, his breathing evening out, when she was utterly spent, teetering on the edge of unconsciousness from pure exhaustion.
The implication pricked at her pride. Did this mean she was physically weaker than him?
That thought alone was enough to make her scowl. Her superior strength had always been a point of secret pride, especially compared to Yumi.
She could easily lift him up and run around carrying him without issue. Yet last night, all that strength had evaporated; she'd been reduced to clutching the bedsheets, utterly at his mercy while he, well, did as he pleased.
Her gaze drifted back to his peaceful, sleeping face. A spark of pure, petty annoyance flared within her. Almost on instinct, still tangled in the sheets, she drew her knee up and gave him a solid, deliberate nudge in the side.
"Ack!"
The satisfying yelp and the sight of him clutching his ribs, his eyes flying open in confused pain, brought a small, triumphant smirk to her lips. It was a minor victory, perhaps, but it felt like necessary compensation, a tiny reclaiming of ground after her total defeat the night before.
"An interesting way to say good morning," Yumi said, turning back to face her.
Celina huffed under her breath, gaze snapping away like looking at him too directly would make her remember everything again, like it had replayed itself in her head the moment she opened her eyes.
Her cheeks were still warm. Her composure wasn't.
Even after what happened, even after the quiet aftermath, she still couldn't decide what she was supposed to feel when he looked at her like that. Comfortable? Confused? Both? None of it fit neatly into the way she normally handled things.
Yumi only smiled, unbothered by her refusal to meet his eyes. He leaned a little, voice calm enough to be unfair.
"So… what does that make us now?"
The question hung there.
Not dramatic, just honest. Still, it made the room feel smaller, like the air had thickened around them. For a moment, neither of them moved, and the silence became its own kind of pressure.
Celina swallowed. She honestly had no idea how to answer.
They were close. Roommates. Comfortable enough to share space, share jokes, share moments that were easy to take for granted. She did have feelings for him. But her heart wasn't a simple thing, and his emotions were… hard to read.
Yumi didn't make it easy.
He smiled, he talked, he acted confident, yet somehow he always kept something just out of reach, like there was a part of him that refused to be fully understood. And once you realized he was the kind of person who lied when it benefited him, trusting his intentions became its own battlefield.
"I… I'm not sure," Celina admitted, voice quieter than she expected.
Yumi didn't push. He just adjusted slightly, shifting so his head rested on his hand. Their legs still touched under the blanket, warm and familiar, like a reminder that the question wasn't theoretical anymore.
Then he said it, simple, straightforward, almost like he was talking about breakfast instead of something that could change their relationship forever.
"Then I'll be waiting for your answer," he said. His golden gaze found her, careful and direct. "Celina, I value you. Whatever decision you make."
He paused, as if giving her room to breathe.
"Whether you accept me… or reject me for who I am."
The room was dim, the curtains softening the light into something muted. Still, it was enough to catch her features, her hair loose, her expression unsettled, her bare leg tucked under the blanket as if she could hide her nerves by covering them.
"I'll honor it," Yumi finished.
Saying it out loud felt like a small decision of its own.
And just like that, the anger and confusion she'd been clinging to earlier finally loosened.
Celina let out a loud chuckle, the sound surprisingly natural. The tension in her shoulders eased, replaced by something lighter.
"You really are hopeless," she said, tone half-joking, half-amused. "And the fact that you'd dare say something like that… after taking a girl's first time."
She shook her head like she was trying to erase the strange images from her mind.
"If others knew you took a girl's virginity and then casually said something like that, you might get beaten to death."
Yumi's expression didn't change much; only his confidence seemed to get sharper. He tilted his head, as if the threat didn't register.
"They can try," he replied with a casual shrug. "I'm the strongest after all."
That smug, arrogant tone… the one that always made her want to roll her eyes.
He made Celina sigh again, but this time it wasn't annoyed. It was… familiar. She smiled despite herself.
Then she lifted her bare leg from the blanket, white fabric sliding over her skin as she angled her body and kicked him squarely.
"Idiot," she muttered, though her voice had no real bite left in it.
After that, the two of them finally got dressed and began making their way toward Duel Academy, though by that point they had already missed the entire morning class schedule, which meant they would at least have to catch the evening classes if they wanted to avoid falling even further behind.
The walk back was supposed to be simple enough, but before long Yumi suddenly felt his senses flare, and the next instant his attention was drawn toward a massive pillar of white light rising somewhere on the island. It spread outward with startling force, glowing fiercely as it swept across the area and washed over Duel Academy itself, and for a moment the brilliance was so overwhelming that it felt like the world around them had been replaced entirely.
"What the!?"
Celina looked around in confusion, only to freeze in place when she realized that the landscape around them had changed completely. Duel Academy was still there, along with part of the mountain it sat on, but everything beyond that had become an endless desert of white sand, stretching in every direction as far as the eye could see.
Yumi's eyes narrowed.
"Chaos!"
At his call, Contrast HERO Chaos appeared before him in a burst of energy, the half-black, half-white HERO standing behind him as his long scarf waved lightly in the strange desert wind.
The moment he arrived, Chaos moved at once, leaping forward and driving a rider kick straight into the Two-Headed King Rex that had lunged toward them, sending the massive dinosaur spirit flying backward from the force of the blow.
Chaos landed smoothly back on the ground, while above them three Harpie Ladies suddenly swooped down in a tight circle before diving toward Yumi all at once.
Yumi did not even bother looking up.
"Galaxy-Eyes."
In response, Galaxy-Eyes Photon Dragon materialized overhead with a thunderous roar, and in the next instant, its photon ray blasted the Harpie Ladies out of the sky before they could even reach him.
Then, almost immediately afterward, a black-armored ninja lunged out from the shadows behind him, trying to strike from the blind spot. Yet before the kunai could reach its target, Dark Law rose out of the darkness and caught the ninja by the head with one hand, stopping it in place before it could land the attack.
Dark Law slammed the ninja's head into the ground, then kicked it away without hesitation.
Not long after that, a large tiger spirit emerged with a threatening roar, apparently trying to intimidate Yumi and Celina with sheer size alone.
Yumi simply stared at it for a moment before calling out, "K9-ØØ... Hound."
The humanoid werewolf spirit appeared at once and stepped forward to meet the tiger head-on, releasing an even more ferocious roar that made the other beast hesitate for a brief moment.
"Cat Dancer."
This time, Celina's Lunalight Cat Dancer appeared before them.
Yumi turned toward Celina with a serious expression.
"Celina, we're inside one of the Spirit Worlds right now, which means Duel Spirits can manifest in physical form here."
He then turned slightly and gestured toward Cat Dancer.
"Take her back to Duel Academy, and keep her safe."
Cat Dancer nodded once, her expression just as serious, before stepping forward and lifting her Master up with surprising ease.
"Hey! Wait a minute, Yumi, what about you?" Celina asked in alarm as she was suddenly picked up, clearly not expecting to be moved so quickly.
Yumi looked back at her.
"I can't go back to Duel Academy yet," he said honestly. "Unlike you and everyone else there, I haven't dueled that much, and right now I've got a large amount of Spirit Energy built up."
He glanced past her toward the dozens of Duel Monster Spirits that were now beginning to gather around them, only for his own Spirits to rush forward and cut them down before they could get any closer.
"Duel Monsters draw strength from Spirit Energy," he continued, his tone calm despite the chaos around them. "To them, everyone else probably looks like bones with a little meat still hanging on, while I look like an all-you-can-eat buffet."
That was the simplest way he could explain it, and honestly, it was not far from the truth.
Ever since coming to Duel Academy, he had repeatedly been targeted by Duel Monster Spirits that did not belong to him, so he understood their nature better than most people would have expected. He knew exactly what they wanted, and he knew exactly why they were drawn to him.
"Get into Duel Academy," Yumi said, a faint smile appearing on his face. "I'll stay outside and protect all of you."
That smile, however, did little to ease Celina's worry.
"After all," Yumi added, sounding as confident as ever, "I'm the strongest, so it makes sense that I'm the one protecting the people who are weaker than me."
With that, he turned away and raised his hand, summoning Raye and Roze beside him as if to make his point even clearer.
Cat Dancer did not linger any longer than necessary. She quickly turned and rushed toward the academy with Celina in her arms, while Celina could only look back over her shoulder at Yumi's retreating figure as they made their way inside the school building.