The Low Cities had grown restless.
Not with rebellion, not with crime—but with a subtle sense of wrongness. People whispered of shadows that didn't belong, winds that moved against the flow of the streets, and a boy whose presence made the world hesitate.
Kairo felt it too.
Every step, every breath, every heartbeat tugged at the seal, pulling it taut against the edges of his body. The longer he ignored it, the more the world seemed to bend subtly—objects tilting toward him, shadows leaning unnaturally, even people's gazes lingering too long.
Sereth watched him quietly from the edge of the alley where they had been hiding. Her jaw was tight.
"Kairo," she said softly. "You can't keep going like this. The seal isn't just unstable—it's learning from you. And right now, it thinks survival means everything bends around you. That's not safe—for anyone."
"I know," Kairo admitted. His hands flexed as he looked down at them, the faint crimson mark still pulsing beneath the skin. "But I can't let it break again."
"You won't have a choice if we do nothing," Sereth replied. "It's time to stabilize it—but doing that will cost you."
Kairo's stomach turned. "How much?"
Sereth's eyes softened, but the edge in her voice remained. "Enough that you won't feel normal for a long time. Enough that every human instinct will fight it. But—if you don't do it, the next time someone—or something—pushes at you, it won't be just your chest that breaks. It could destroy everything around you."
Kairo swallowed. "Then… I'll do it."
They went to the abandoned cistern again, the same place where the Judges had fallen and Sereth had nearly sacrificed herself. The space smelled of damp stone and old fear, but Kairo felt ready. Or at least as ready as he could be.
Sereth gestured to him. "Focus on containment, not control. Not restraint. Containment. Let the seal learn its limits, but don't let it take your will. Your mind, your intent, your humanity—they have to anchor it."
Kairo nodded, steadying his breathing.
The seal flared.
Not wildly. Not angrily. But it reacted. Threads of dark light pulsed across his chest, climbing up his shoulders and down his arms. The mark burned hotter than ever before.
"Focus," Sereth said. "Feel your body. Let it learn itself."
Kairo clenched his fists, gritting his teeth as pain exploded across his ribs, his shoulders, his back. His body screamed at him—not just the muscles, but the bones, the sinew, the very blood coursing through him.
The world around him shifted. Shadows recoiled. Stone groaned. The air pressed too close.
And then, he reached out—not with power, but with himself.
Every thought of fear, every instinct to flee, every flinch, every hesitation—he corralled it. Not with force. Not with anger. With choice. He anchored himself in the human part of him—the part that refused to kill, the part that refused to bow, the part that refused to leave Sereth behind.
The seal pulsed violently.
Pain ripped through him, more intense than ever, but the threads of shadow and light slowly aligned. Slowly bent to his intent. Slowly contained themselves within the limits he was setting.
Hours passed—or maybe minutes. Time lost meaning.
When Kairo finally collapsed, he didn't gasp for breath. He didn't scream. He simply lay there, drained, his chest burning faintly as the seal rested quietly for the first time since Raizen had sealed it in him.
Sereth knelt beside him, placing a hand on his shoulder. "It's done," she said softly. "The seal… it listens now. It's contained."
Kairo's fingers twitched, testing the weight of his own body. It felt foreign—like learning to walk again—but stable.
"You've paid the price," Sereth said. "And now… you can move without tearing the world apart."
He nodded slowly, exhausted. "I didn't think it would hurt like this."Sereth smiled faintly. "That's what staying human costs. But it's worth it."
Outside the cistern, the Low Cities continued as though nothing had happened. Shops opened. Children ran in alleys. Lanterns flickered in the night wind. The world moved on.
But deep inside Kairo, the seal pulsed quietly, aware, obedient, but restrained.
And far away, in the shadowed halls of the Council, monitors flickered with static.
A new problem had arisen.
One they could not simply erase.
A boy had stabilized a Demon King's power—and he had refused to become one.
The world would notice soon enough.