The origin of everything should begin with a child.
Tenjo Haruto.
A little over a decade ago, Dr. Faker had a second child outside of Tenjo Kaito, a charming and intelligent child named Tenjo Haruto.
But from birth, Tenjo Haruto was very fragile, whether in body or mind. It seemed that due to his innate "talent," his body was equally weak, forcing Dr. Faker to make a choice to save his son.
"Dr. Faker is a genius," Kurosaki Shun said sincerely.
Most of the recent inventions in the Xyz Dimension actually originated from Dr. Faker. He created Heartland, invented Heartland City, developed countless new cards, harnessed the power of the Galaxy, and even created fully intelligent AI. He is a genuine genius.
Yet, even a genius like him couldn't avoid despair when faced with his son's predicament.
His talents, his wisdom, his inventions, all seemed like jokes in the face of this incurable disease. He could create immeasurable wealth and bring progress to humanity in his world, but he couldn't find a way to save his own son.
In such despair, that [person] appeared.
The Goddess of the Dark World, a being that can appear to those in despair.
The Goddess of Despair, E'rah.
That entity taught Dr. Faker a method.
To reach out to the Varian Realm, a world that holds a solution to Haruto's condition.
Faced with despair, Dr. Faker didn't hesitate for a second—he couldn't save people, but could he not find a way to contact the Varian Realm?
To save his son, he sacrificed two of his genius friends, finally making contact with the existence of Varian and forming an agreement with that dimension. Dr. Faker planned to create something that could destroy the Starlight Realm, while Varian Realm would provide the power to sustain Haruto's life.
Until long ago, when the No. cards appeared in the Xyz Dimension, Dr. Faker's plan began true implementation.
A group of young girls sat around, listening to Shun talk about things they had never heard of, becoming increasingly fascinated, especially Ruri. Despite also being from the Xyz Dimension, such matters were highly confidential information that ordinary people never had the chance to know.
Why does Shun know?
Apart from being at the scene watching duels, there was another very important reason: he was a student of the Arclight Family—in fact, he was the student of the eldest son of the Arclight Family, "V" Christopher Arclight.
It was for this reason he had the privilege of meeting Tenjo Kaito.
However, Tenjo Kaito never knew he had this "junior"—after all, V genuinely taught Kaito as an apprentice, while Kurosaki Shun was more of an experimental subject for attempts of instruction.
But there's no need to tell Ruri about these things. Seeing Ruri's curious expression, Shun softened his tone and began to explain more profound matters.
"The father of my teacher sought to take revenge on Dr. Faker."
"Revenge? Why? What grudge?"
"Ruri, have you forgotten? I just said... Dr. Faker sacrificed two friends who were exploring with him to find the Varian Realm."
"!!!" Ruri covered her mouth in shock.
"Could it be..." Rin thought of a possibility.
Shun nodded.
The head of the Arclight Family, the father of the three brothers, who called himself "Tron," was one of the two friends Dr. Faker deceived and sacrificed to find the Varian Realm.
He spent a long time in the void, unexpectedly finding his way into the Spirit World, where he researched and developed the "Power of Emblem." With this power, he found his way back, seeking revenge.
He kidnapped Haruto, took away Haruto's power; he deceived Kamishiro Ryoga into falling into his trap; in the end, using Haruto's appearance and schemes, he prevented Kaito from fully focusing on dueling, defeated Kaito, and gained the strongest human power on Earth, intending to use the power of No. cards to avenge Dr. Faker.
Fortunately, at this moment, someone appeared whom Shun found hard to describe.
Tsukumo Yuma.
He was just an ordinary kid.
Kurosaki Shun met him during the Fusion Army's invasion, a kid even younger than Yuto but with a peculiar quality.
Not only did he save ordinary people during the invasion, but later on, he even chose to rescue... the Fusion Army!
Yes, many of those Fusion Army soldiers, treated as pawns, chose to hide and survive once they realized they were mere discards. But they didn't have separate dimensional teleportations; they could only live hidden, like rats in a gutter, in this strange world.
If it were Kurosaki Shun who found these invaders, he would undoubtedly turn them all into cards—using the card-transforming technology seized from the Fusion Army!
However, after that, Tsukumo Yuma saved a lot of Fusion Army soldiers, every single one that did not harm others, who ran away upon arrival, who hid. He didn't want to abandon any of them.
It's ridiculous, so even though Shun initially felt good about the little one who helped others, he couldn't accept Tsukumo Yuma's actions at all after the incident of Ruri's kidnapping.
But Tsukumo Yuma continued to persist in this way, even after several conflicts with him, Yuma continued to persist, hoping he could also help those ordinary people.