Mitsuni felt her heart tighten as she watched the familiar black veins reappear on Yuki's neck once again. This wasn't the first time.
"Again...?" Mitsuni whispered, her voice trembling. "These black veins… this is the third time this month. But this one was much more intense."
Sora-san and the others looked at Mitsuni in shock. When Mitsuni took Yuki's hand, she noticed that his skin was still hotter than normal. The black veins that had surfaced just moments ago were actually taking root deeper into his body each time and lasting longer.
Mitsuni turned to the people in the room and explained the situation clearly:
"Before, when we saw these, we thought it was just fatigue or some reaction caused by Quiri energy. But we were wrong. Every time these veins appear, the Quiri essence inside Yuki is merging even further with his human tissues. I used to wonder why Yuki's family wanted to sacrifice him, but now I understand. These veins appear when his body fails to react properly to certain things — just like how it reacts to Quiri energy. The only difference is that the veins turn black."
She paused, then continued:
"When I looked at Yuki's body, I noticed how unusually thin his skin was compared to a normal child's, and how some of the bruises appeared without any reason. That's when I started suspecting Bam Syndrome… and I was right. Once Bam Syndrome begins, it never truly stops. It only goes dormant."
Kaito stood at the doorway, watching his unconscious brother's labored breathing, his fists clenched tightly.
Mitsuni continued:
"Yuki's body has become a battlefield. These black veins aren't just a symptom — they're the process of Quiri energy converting his blood into its own fuel. If these attacks keep happening more frequently, the next time the veins appear, they might not disappear. Then Yuki… he won't be okay at all."
Mitsuni couldn't finish her sentence. The heavy silence in the room grew even heavier.
"He won't be okay at all…" she repeated in a whisper, as if trying to suppress the fear rising inside her. Everyone understood the horror hidden in her unfinished words: Yuki was no longer just a child. He was a Quiri bomb ready to explode.
Mitsuni gently placed Yuki's hand back down and stood up. Her eyes lingered on the ghostly black marks that had appeared across the boy's pale skin.
"You don't understand," she said, turning to Sora-san and Lady Akira. "I always wondered why Yuki's family wanted to sacrifice him, why they gave up on their own child. It couldn't have been just blind faith. They knew. The unnatural thinness of his skin, those unexplained bruises… they weren't from malnutrition or accidents. His body is being torn apart from the inside while trying to contain this foreign energy. Bam Syndrome is the most severe allergic reaction a body can have to Quiri energy. Normally, when a cell encounters something foreign, it tries to destroy it. But Quiri energy can't be destroyed — it only settles in. And every cell it settles into turns black."
Kaito stood frozen in the doorway, listening to his unconscious brother's raspy breathing. His fists were clenched so tightly that his knuckles had turned white.
"And then what?" he asked, his voice trembling with icy anger. "What happens when these veins become permanent, Mitsuni? Will my brother turn into a monster?"
Mitsuni swallowed hard.
"In the final stage of Bam Syndrome, the body completely rejects human biology. The veins stay black, the heartbeat slows, and body temperature drops to that of a corpse. If we can't stop this process, Yuki's consciousness will drown inside that dark energy. The person standing before us won't be Yuki anymore — just a shadow made entirely of Quiri, a vessel that uses his memories."
Just then, Yuki twitched again in his sleep. An incomprehensible word slipped from his small lips. Sora-san immediately knelt beside him and wiped the sweat from his forehead, but the boy looked as if he had fallen into a nightmare-filled void.
Lady Akira walked over to the window and gazed into the darkness outside.
"What Alex said and Yuki's current condition are not a coincidence," she said in an authoritative voice. "The way the Couriers can take human form is connected to the changes happening inside Yuki's body. It's as if someone has been using him as a test subject to see how much Quiri energy a human body can withstand."
Mitsuni's eyes widened in horror.
"Like a lab rat…?" she asked, terrified.
Zen-kun and Kazeki huddled together in the corner of the room, trying to process the dark truth behind the adults' words.
Haruto, who had been forced by Kaito to stay out in the hallway, was still shouting from outside.
"Time is running out," Mitsuni said with a determined voice. "The next time these veins appear, they won't stop at the surface of the skin — they will reach Yuki's heart. To save him, we don't just need medical treatment. We need a spiritual sealing ritual. But that sealing might rip away Yuki's own power as well. And if his power is taken… I don't know if this fragile body can survive it."
The room fell back into a heavy silence, where every breath felt like a burden. Yuki's pale face was the quietest yet most painful proof of the coming storm. Bam Syndrome was growing like a black hole, slowly pulling them all in.