The scent of blood and burned silk filled the air.
Tanjiro stood on the rafters, face flushed, breath ragged. The air around him shimmered with residual heat. His blade dripped demon blood, his heart still racing with fury.
Across from him, Daki, Upper Moon Six, staggered in shock.
"How… how did you cut me?!"
Her severed hair fluttered through the air like petals. A deep, raw gash marked her neck.
Tanjiro's Sun Breathing style had overwhelmed her elegance and speed. She had never encountered that flame—that ancient technique—and for the first time in centuries… she faltered.
"You're not supposed to have that kind of power!" she screamed, her voice shrill and furious.
But Tanjiro did not respond.
His body swayed—he was near his limit.
And yet, when she lunged again—
"Hinokami Kagura: Flame Whirl!"
A final arc of searing light separated her head from her body.
Daki froze. Her lips trembled.
The world spun.
"No… no, no, NO—!"
Her head thudded to the floor with a dull crack.
But she didn't die.
Tanjiro's brows furrowed.
Her body remained still… and yet the scent—the malevolent aura—was not fading.
Instead—
It was growing.
From the earth beneath, the floor split open like a wound. Blood erupted upward, soaking the tatami.
A new voice, rasping and venomous, slithered through the air.
"That's my sister you just hurt, boy…"
From beneath the floorboards, a tall, skeletal figure emerged. He was hunched, skin green with rot, adorned in tattered rags. His back erupted with boil-like growths, and his eyes gleamed like cracked glass.
Gyutaro.
The other half of Upper Moon Six.
"And I don't like it… when people touch my little sister."
His flesh scythes slid out from his arms like bone-carved blades. In one motion, he spun—slicing the very air in a spiral of crimson slashes that forced Tanjiro back.
Daki's headless body twitched—and the moment her head touched it again, she rose.
"Onii-chan… I'm so sorry…"
"No need to cry, Daki," Gyutaro crooned, voice rattling like chains. "Big brother's here now. Let's kill them together."
Tengen Uzui arrived in a blur of silver and purple. His dual blades clanged as he deflected a wave of Gyutaro's blood blades, his body already moving faster than sight.
"Two of you, huh?" he muttered. "That's… flashy."
Zenitsu, Inosuke, and the barely conscious Tanjiro regrouped behind him, tension rising.
Tengen sized up Gyutaro. "So this is the real Upper Moon Six."
Gyutaro grinned. "You're not bad-looking. I hate you already."
Then the district exploded into chaos.
Zenitsu, moving at lightning speed, rushed Daki in her fused state, clashing again and again through the falling rubble of the brothel.
Inosuke carved through Daki's tendrils, maneuvering with wild unpredictability, keeping her sash attacks in check.
Meanwhile, Tengen engaged Gyutaro directly in a whirlwind of movement and death. The Hashira's chained blades gleamed with poisons meant to kill demons, but Gyutaro matched each strike with his deadly blood scythes.
Tanjiro, worn yet driven, watched for openings—his breathing shaky but determined.
The siblings moved with eerie coordination.
"They're fighting as one," Tengen muttered.
It was a two-on-four, but the pressure was overwhelming.
Gyutaro's blood demon art spread through the district, turning the air itself into a trap of slicing needles.
Even with all their strength, the Demon Slayers struggled to gain ground.
And then…
A shift in the atmosphere.
Like the sun rising before dawn, a warmth rippled through the battlefield.
Gyutaro's eyes narrowed.
Daki paused mid-swing.
They all felt it.
From above—on the roof of the main brothel—a figure stood with arms folded.
Black coat. Crimson edges. Sun sigil embroidered across the back.
Tharion.
The moonlight hit the gleam of his sword's hilt. No emotion marked his face, no urgency, no fear—only a quiet, inevitable certainty.
"So these are the two you've been hiding, Muzan…"
His eyes locked on Gyutaro, and in that instant, the demon felt something ancient claw at his memories.
A primal fear.
"No… not that man…"
Tharion drew his sword.
It blazed like sunrise.
"This farce ends now."