A few minutes earlier.
The white and red D-Wheels were driving side by side under the vast and boundless night sky, the tires carving two long arcs through the desert.
Youyu and Yusei maintained a steady pace as they traveled across the endless wasteland, nothing but barren land in sight, with no sign of any living being.
"This world feels so desolate," Yusei said as he looked around.
"Maybe it's the impact of the war they mentioned," Youyu casually replied. "The vampire just said that all the people in the town fled upon hearing news of the war.
It's possibly for similar reasons that there's no one around here."
Even in the Otherworld, there's no need to worry about fuel running low when driving a D-Wheel. That's one of the strongest aspects of D-Wheels as a vehicle.
The engine of a D-Wheel is called a "Moment" for a reason. In whichever world or dimension, a Moment can keep running forever without stalling.
But, the so-called Moment is, to some extent, a fake. Because the Moment isn't a machine that can unconditionally operate forever; it's more like a somewhat idealized black technology. It requires the passionate spirit of the Duelist to fuel it, allowing it to truly operate eternally.
Simplistically, it's like saying everyone has to maintain a card addiction and stay highly passionate about card playing... (President Haima calls this getting the hang of it)
After a brief silence, Youyu turned to look at Yusei and finally asked, "We haven't had a chance before, but can we talk about this now?"
Yusei was slightly taken aback, "About what?"
"The reason you came back to this era."
Yusei: "..."
Seeing Yusei not intending to speak after a moment of silence, Youyu continued, "If you don't want to talk, let me give my observations, then?
Firstly... I guess you've already met Z-ONE?"
Yusei showed a surprised expression.
"So Mr. Youyu... you already knew about Z-ONE at this time?"
"Yes, I've encountered him before," Youyu said. "Moreover, I noticed the 'dragon mark' on your hand is gone.
So, going a bit further... I guess you've already defeated Z-ONE, right?"
Yusei appeared even more surprised.
"Honestly, even coming back from the future, Mr. Youyu, you still remain inscrutable to me," Yusei said.
Youyu chuckled.
This prediction was actually based on the plot of the animation. Throughout the Yu-Gi-Oh! 5D's animation series, Yusei always had the 'dragon mark' on his arm, symbolizing the power bestowed by the Red Dragon.
Until the finale, when Yusei defeated the final boss "Z-ONE" spanning three seasons of the animation, the dragon mark disappeared from his hand.
Besides, another obvious point was when Yusei summoned 'Shooting Quasar Dragon' during their previous duel, a card he only printed during the animation's final battle.
"I'm becoming more curious about how much you actually know," Yusei smiled slightly. "However, some things you said aren't entirely accurate."
"Oh?"
"Regarding Z-ONE," Yusei said. "I indeed encountered him and battled him like you, Mr. Youyu. But...
...Well, the situation is a bit complex, but he isn't defeated yet."
Youyu showed a somewhat peculiar expression.
The Crab's Shooting Quasar Dragon is printed out, and yet Z-ONE isn't done?
Is the Red Dragon Card Printer not potent enough?
Or perhaps... Z-ONE, this already extraordinarily formidable boss, got updated to be even harder to deal with than in the original?
"As I said earlier, the situation is complicated. That's also why I returned to this era," Yusei explained. "Something significant is about to happen in this era that may directly influence future developments. Therefore..."
He stopped abruptly, like swallowing the rest of his sentence.
Youyu quickly realized why.
Almost simultaneously, both of them instinctively hit the brakes. The two D-Wheels stopped in place, their arcs intersecting in the desert.
There was someone else... or something else coming.
Black mist gradually rose, converging from all directions. The rocks in the distance became blurry within moments, leaving only rugged outlines visible, then soon disappeared altogether.
What's even eerier was the sudden appearance of a round moon in the sky, glowing with an uncanny brightness, as scarlet as blood, sending chills down one's spine.
Youyu quickly connected this to the eerie red moon depicted on the Vampire series card images.
Rhythmic hoofbeats sounded from nearby, growing louder in their ears as they steadily approached.
A dark silhouette emerged from the other side of the mist, piercing through the haze. A black horse rapidly closed in, with a knight sitting atop it, holding a lance, his face hidden in the shadow of his helmet, appearing as cold as a corpse.
Vampire Red Baron.
One of the generals in the Yu-Gi-Oh! Vampire series card deck, presumably one of the notable figures in this dimension.
The Red Baron approached on horseback, swung around holding the reins, and came to a halt, the horse's hooves kicking up a storm of dust.
His gaze passed coldly over the two, pausing notably on the Duel Discs mounted on their D-Wheels.
Then he slowly lowered the hand holding the lance, hanging the spiral weapon to the side of the horse. He raised his other hand, from which a writhing black entity extended, slowly solidifying into a form resembling a Duel Disc.
And then, surprisingly, a rough voice emanated from under his helmet.
"Unexpected to see 'cavalry' even among Otherworld warriors," he said in a dull tone. "Do you dare, then, to accept the trial of 'Riding'?"
Youyu and Yusei exchanged glances.
"Tell me you understand it the same way," Youyu raised an eyebrow. "Is this guy saying..."
"It should be," Yusei nodded, though his expression also carried some peculiarity. "This guy's meaning... should be 'Riding Duel'?"
As he spoke, he glanced at the seemingly undead black horse underneath the Red Baron.
"...Using his horse?"
Youyu pondered, realizing it might actually not be unheard of.
The animation didn't mention it, but in the Yu-Gi-Oh! 5D's manga, it's specifically detailed that "Riding Duel" wasn't a modern invention, and ancient Duelists also had special rituals of dueling while riding.
Obviously, back then, there was no modern technology like the D-Wheel, so all Duelists engaging in Riding Duels at that time rode horses as their mounts.
At the start of the 5D's manga, Fudo Yusei encounters "Skeleton Knight," a Riding Duelist from ancient times. Skeleton Knight was riding a horse when he first battled Yusei on his D-Wheel.
"This seems interesting," Youyu appeared intrigued.
"I'm quite experienced with Riding Duels," Yusei offered. "Let me take this one."
"No, leave it to me," Youyu said with a mysterious smile, glancing at Yusei. "But I do have a request. I'd like to borrow your D-Wheel."