Upon reaching the backyard, Galen carefully placed Kayn on the grass. Kayn thought about running away, but perhaps that would have been going too far. He looked around, taking in the garden where they had spent countless hours training. It was at the age of four that he first wielded a wooden sword. He could still hear his mother’s protests as she scolded Galen for teaching such a young child to handle a sword. Since then, his skill had grown stronger through constant practice.

On his eighth birthday, he had been given his first real sword, which he still kept alongside the rest of his weapons. Though now it was broken—after an ill-advised attempt to cut through a stone, just as his father had done.

Lost in thought, he didn’t notice something flying toward him until it was about to hit. Instinctively, he raised his hand and caught a wooden sword in mid-air. He examined it in confusion, turning it between his fingers. They had been practicing with real swords for some time now; why go back to training ones?

“Why are you giving me this? I’m not a little kid anymore. If we’re going to train, I want to use a real one.”

“And risk having a problem with how riled up you are?” Galen replied, teasing his son. “No thanks. Your mother’s upset enough without giving her something else to worry about.”

“Fine, but just for a little while,” Kayn sighed, gripping the polished wooden sword.

“That’s the spirit.” Galen tossed his shirt to the ground, revealing his sculpted muscles. “Come on, attack whenever you’re ready.”

Without hesitation, Kayn charged. His feet moved nimbly across the grass, closing the distance in the blink of an eye. He thrust straight at his father’s chest, hoping to land a blow, but Galen easily deflected it with a slight movement of his sword.

Frustrated, Kayn pivoted on his heels and swung a horizontal slash aimed at Galen’s side. His father blocked it again, this time without even stepping back. The unshakable smile on Galen’s face only fueled Kayn’s irritation.

“Is that all you’ve got?” Galen teased, taking a light step backward. “No wonder no guardian wanted to bond with you.”

“Shut up!” Kayn snapped, his frustration boiling over.

Gritting his teeth, Kayn stepped back and lunged again. He increased the speed of his strikes, abandoning precision in favor of relentless attacks, mixing feints with blows from different angles. His breathing quickened, and he put more force into every movement, but Galen dodged and parried with an almost insulting ease.

Kayn swept low, attempting to trip his father, followed by a rapid thrust aimed at his shoulder. Galen lightly jumped over the sweep and turned, dodging the thrust that passed mere inches from his neck.

“Are you even trying?”

Kayn roared, swinging downward with all his strength. Galen sighed, raising his weapon to block. The wooden swords collided with a sharp crack that echoed through the garden. The impact forced Kayn to step back, stumbling as he panted from the exertion. Sweat dripped down his forehead, and his hands began to tremble slightly.

Why? Why can’t I land a single hit?

“You’re wondering why you can’t hit me, aren’t you?” Galen said, his infuriating smile still intact. “Anger clouds your judgment. When you fight, you need a calm mind. Otherwise—”

“I know that! I don’t need your lessons right now!”

Without waiting for a response, Kayn lunged again, but his movements were more erratic this time. The sword felt heavier in his hands, and each strike grew less precise than the last. Galen sidestepped easily, letting Kayn rush past him. The boy lost his balance and fell onto the grass, feeling the dampness and the smell of fresh earth beneath him.

Kayn placed his hands on the ground, feeling sweat drip from his forehead onto the grass. His breathing was labored, and dizziness began to creep in from the effort.

“You’re wasting your energy like this. Focus more,” Galen said, pointing his sword at him.

“Don’t tell me what to do!”

Kayn leapt to his feet and launched another desperate attack. But before he could finish the motion, Galen stepped forward and struck Kayn’s wrist with precision. The wooden sword flew from his hands, spinning through the air before landing several feet away. A sharp pain shot through his arm, and Kayn clutched the spot where he’d been hit.

“Damn it…”

“That’s enough. We’re just wasting time like this,” Galen declared, fixing his gaze on his son. He let out a deep sigh before sheathing his sword at his waist.

Kayn’s eyes filled with tears of frustration as he fell to his knees, staring at the ground. The green grass blurred before his tear-filled eyes.

“Why? Why can’t I get this out of my head?” Kayn growled, punching the ground. “I was so excited for this day. Now I’ll never be like you or Grandpa. No guardian accepted me. I’m a complete failure.”

“That’s why I told you not to get your hopes up…” Galen muttered.

A heavy silence hung between them, broken only by the soft whisper of the wind. Slowly, Galen stepped closer and placed a firm yet gentle hand on his son’s shoulder.

“Listen to me. You’re not a failure. You’re stronger than many kids your age.”

“What good is that if I can’t be a bonder?” Kayn shouted, his tears falling freely. Seeing him like this, Galen ran a hand through his hair and turned his back.

“I wanted to wait a bit longer to tell you, but I think it’s time.”

“What are you talking about?”

“I know this will sound strange, but… you can still become a bonder,” Galen said, turning to meet his son’s gaze.

Kayn blinked, surprise flashing in his eyes before suspicion took over.

“You’re joking, right?” he asked, clearly upset. “I failed the ceremony. If a guardian didn’t react to my anima today, it never will. Everyone knows that.”

“The bonding ceremony isn’t the only way to become a bonder,” Galen replied. “Though it’s the conventional method.”

Kayn stared at him, bewildered by what he was hearing. It was the first time he had ever heard such a claim. Becoming a bonder was the term used for humans who managed to bond with a guardian. It was through this bond that humans could rival the other species, who were naturally gifted with magic. So why was his father saying this? He didn’t seem to be lying. In fact, he had no reason to. Could he be serious?

Noticing the confusion in his son’s eyes, Galen continued.

“Don’t worry, it’s normal to feel confused. This isn’t something someone your age would know about. And besides, there aren’t any labyrinths nearby.”

Labyrinth. It was the first time Kayn had heard the term, but it seemed connected to this alternative method of becoming a bonder. Asking more questions would only make his head hurt. It was better to let his father explain everything.

“What’s a labyrinth?” Kayn finally asked.

"Let me think where to start," Galen said, scratching the back of his neck. "After graduating from the Bonder Academy, but before joining the Royal Guard, I spent some time as an adventurer."

Kayn already knew that story. His father had told him countless times about his days as an adventurer and later as a member of the Royal Guard. Those tales were his bedtime stories. However, an injury to his leg during a mission had forced Galen to retire. He couldn’t move as well as he once did, and now he mostly trained just to stay in shape.

"While I was an adventurer, I heard stories about incredible dungeons filled with treasures and powerful relics. But none of that compared to what was hidden in their depths."

"Why were they called labyrinths?"

"Let me tell you the story my guildmates shared with me," his father began, clearing his throat before continuing. "It happened about twenty years ago, shortly after the War of Discord came to an end. Back then, I was still at the academy."

In a remote human village, a mysterious door suddenly emerged from the depths at the foot of a mountain. The villagers, frightened, approached to see what it was. The idea of entering terrified them, but a few brave souls gathered the courage to venture inside. Days passed, and the villagers waited for news about what they had seen, but those who entered were never seen again. Despite this, more and more people ventured in, yet not a single one returned.

When it seemed impossible to escape from the dungeon, one day, someone emerged alive. It was a man covered in bruises and utterly exhausted. He was severely dehydrated, as though he hadn’t drunk water in days, though only a few hours had passed since he entered the labyrinth. The villagers were confused when they recognized his face. He had gone in with a group of twelve people, including seven bonders. Yet, he was the only one to return. To make matters worse, he wasn’t accompanied by his guardian.

The villagers bombarded him with all kinds of questions, but the look in his eyes was one of profound horror. He was traumatized by what he had witnessed. After letting him rest for a few hours, he recounted what he had seen. Beyond the door lay a dungeon unlike any he had ever entered before. He had never encountered monsters with such overwhelming strength. But the most terrifying part was what awaited him at the end of the dungeon: a vast chamber where an enormous spirit began to judge everything he had done inside the labyrinth, mentioning the sacrifices of his companions and even his cowardice during certain trials. It was as though the spirit had seen everything. The spirit parted with these final words:

"You are not worthy."

Before he realized it, he was back at the entrance where he had first entered. The villagers left him alone, but the man never wielded a sword again. Upon learning there was a way to return, more people began venturing into the labyrinth, this time much better prepared. Even so, only a few managed to return, and those who did were never the same.

A dungeon where people disappeared without a trace, as though they could not find their way back. This is why they came to be known as labyrinths.

Nearly three years passed since the labyrinth first appeared. Not only humans but also other species attempted to enter it, yet none succeeded in claiming a reward. During that time, around ten thousand people lost their lives. The villagers began to lose all hope, but one day, a young man no older than seventeen appeared. He wasn’t heavily armed and wasn’t accompanied by a large group like others before him—only two others were with him. The villagers tried to warn him about the dangers of the dungeon, but he ignored them completely.

Three days later, the ground in the area began to tremble. The villagers rushed to see what was happening and were astonished by the sight. The young man who had entered three days prior appeared before them. But there was something different about him compared to the others who had returned. The door to the labyrinth was closed.

The young man began walking away with the two people who had accompanied him. The villagers ran after him, hoping he would tell them what had happened inside. The young man drew his sword, and after murmuring a few words, an enormous spirit appeared behind him. They thought it might be his guardian, but his actual guardian was still perched on his shoulder. The young man swung his sword, and with a single motion, he opened a massive chasm that destroyed the entire forest. The villagers were left speechless as they watched him walk away without uttering a single word along the path he had just created.

Soon after, more labyrinths began to appear across the world.

"That spirit was...?"

"As you know, guardians are ranked based on their strength or rarity, from E to SS. Pong, my guardian, is ranked A. He's in his final stage and can’t advance any further. In contrast, the guardians from the ceremony, with their long growth potential, can eventually reach the highest rank, though they generally start at rank C." Galen paused, watching Kayn raise an eyebrow, not understanding why his father was explaining something he had already studied in school. Galen continued, "However, the spirits of the labyrinths completely break this classification due to their immense power. That's why a unique rank was created for them."

"What rank?"

"Sacred. Sacred Guardians," Galen replied, his tone solemn. "They say that if you reach the end of a labyrinth and the guardian deems you worthy, it will form a bond with you."