The Demon Slayer Headquarters did not feel like a battlefield.

  That was what made it worse.

  The courtyard was wide and clean, stone tiles worn smooth by generations of footsteps. Pillars stood firm, unbroken, as if they had never known violence. The wisteria trees beyond the walls swayed gently, indifferent to the tension gathering beneath them.

  Tsukiko stood near Shinobu, shoulders tight, fingers curled against her palms.

  Too many people.

  Hashira gathered loosely around the space, some openly watching, others pretending not to. Tsukiko felt every glance like a weight pressing against her skin. Villages had been quiet. Demons had been simple.

  People were not.

  She kept her gaze lowered.

  Don’t breathe too fast.

  Don’t let it slip.

  Sanemi Shinazugawa leaned against a pillar, arms crossed, expression unreadable. Unlike the others, he didn’t stare.

  He already knew.

  “She’s not bluffing,” Sanemi said suddenly, breaking the murmur. “I fought her.”

  Several heads turned.

  “With a wooden sword,” he added. “No breathing. No tricks.”

  Tsukiko stiffened.

  Sanemi’s eyes flicked to her briefly. “She blocked me twice. Stopped my third strike before it moved.”

  A ripple passed through the Hashira.

  “But,” Sanemi continued, voice flat, “I didn’t see her breathing style. That’s what you’re all curious about.”

  Obanai’s mismatched eyes narrowed. “So you’re saying she’s good with a sword.”

  Sanemi shrugged. “I’m saying she’s dangerous even without one.”

  Tsukiko swallowed.

  Shinobu felt the tension coil inside her sister and stepped half a pace closer, a silent anchor.

  Kagaya Ubuyashiki’s voice carried calmly across the courtyard.

  “You believe she hides something.”

  Tsukiko lifted her head.

  “I don’t hide,” she said quietly. “I control.”

  Some scoffed. Others watched more carefully.

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  Rengoku stepped forward, posture straight, expression bright but serious. “Then allow me to test you! Not as an enemy—but as a fellow warrior!”

  Shinobu inhaled sharply. “Rengoku—”

  “It’s fine,” Tsukiko said.

  She stepped forward before Shinobu could stop her.

  “If you hold back,” Tsukiko continued, voice steady but strained, “you won’t understand what you’re facing.”

  Rengoku blinked, then smiled wider. “Very well! I will not insult you with restraint!”

  Sanemi frowned. “Careful.”

  Rengoku laughed. “I always am!”

  They took their positions.

  Tsukiko closed her eyes.

  Just defense first.

  She inhaled slowly.

  Not deeply.

  Not fully.

  She didn’t activate Sun Breathing — she let it circulate, warming her muscles, sharpening her awareness. The heat stayed inside her body, contained.

  Rengoku moved.

  Fast. Heavy. A Hashira’s strike meant to test reaction, not kill.

  Tsukiko blocked.

  Steel rang out.

  The force drove her back a step, stone cracking faintly beneath her heel. Her arms burned, but she held.

  Again.

  And again.

  Rengoku pressed, blade blazing with intent. Tsukiko parried, redirected, slipped past attacks that would have cleaved lesser slayers in half.

  Minutes passed.

  Five.

  Then seven.

  Sweat slid down Tsukiko’s temple. Her breathing stayed measured, but strain crept into her limbs. She felt the heat inside her chest begin to rise dangerously.

  Rengoku noticed.

  “You’re enduring beautifully!” he called, excitement genuine. “But you’re holding something back!”

  Tsukiko exhaled sharply.

  Enough.

  She stepped back.

  Closed her eyes.

  This time, she inhaled fully.

  The air burned as it filled her lungs — not flame, not fire, but something brighter, heavier, ancient. The courtyard seemed to dim as the heat concentrated around her.

  The ground trembled.

  Pillars rattled. Birds burst from the trees.

  Shinobu’s heart stopped.

  Tsukiko opened her eyes.

  They reflected light like polished gold.

  Sun Breathing — First Form.

  She moved.

  Not fast.

  Not wild.

  Perfect.

  Rengoku raised his blade instinctively—

  Tsukiko’s strike never meant to kill.

  She adjusted at the last instant, letting Rengoku deflect it.

  Her blade struck the ground instead.

  The stone exploded.

  A crater ripped open beneath the impact, cracks spider-webbing outward as a shockwave tore through the courtyard. The mansion walls groaned. Roof tiles shattered and fell.

  Silence followed.

  Rengoku landed on one knee, breathing hard, eyes wide with awe.

  “…Magnificent,” he whispered.

  Tsukiko stood frozen.

  Then her knees buckled.

  The heat vanished instantly, leaving behind agony.

  She collapsed forward.

  Shinobu was there in an instant, catching her before she hit the ground.

  Tsukiko gasped, body shaking violently now as the backlash tore through her muscles. Pain flooded her limbs, deep and punishing — the cost of holding the sun inside herself for too long.

  “She fought for over ten minutes,” Sanemi muttered, eyes sharp. “That wasn’t luck.”

  Obanai crossed his arms. “But she can’t sustain it.”

  Mitsuri looked horrified. “She’s hurting herself!”

  Kagaya rose slowly to his feet.

  “She is strong,” he said softly. “And she is burning.”

  Shinobu clutched Tsukiko tightly, fear flooding her chest.

  Tsukiko’s breath came in broken gasps. “…I told you,” she whispered. “I won’t die.”

  Shinobu pressed her forehead to Tsukiko’s. “You don’t get to decide that alone.”

  Kagaya stepped closer.

  “You will not be stopped,” he said gently. “But you will not act without guidance.”

  Tsukiko’s eyes flickered.

  “…You won’t forbid me?”

  “No,” Kagaya replied. “Because power like yours cannot be caged.”

  He paused.

  “But it can be wasted.”

  The words sank deep.

  Tsukiko’s body finally went slack, consciousness slipping as exhaustion claimed her.

  Shinobu held her, shaking.

  Because now they all knew the truth.

  Tsukiko was not reckless.

  She was running on borrowed time.

  And if she burned too brightly—

  There would be nothing left to save.