The battlefield was hell itself.
Japonica 's sky split open with streaks of crimson and gold, firestorms clawing at the heavens.
The earth was ash, every tree burned to cinders, every stone cracked from the weight of titans clashing.
And at the center, the Demon of Hatred roared, its body swollen with endless malice, flames devouring everything in reach.
Klaus, Sofie, Tatsuki, and Isshin stood as one.
Four warriors.
Against one immortal beast born of sorrow and rage.
The air was so hot it peeled their skin. The aura so heavy it crushed lungs.
Yet none of them faltered.
Inside Klaus's soul, Ashborn's voice struck like thunder:
"This is it. The Fushigiri thirsts. It wants the final cut. But you cannot do this alone. You must align your wills… all of you."
At the same time, Sofie heard the Phoenix within her.
"Your flame can bind its body. Burn the immortality away long enough for the blade to strike."
And Tatsuki's Ryōki pulsed.
Isshin.bleeding and coughing, shoulders trembling from dragonrot, spat blood and grinned like a wolf.
The Demon charged.
Its maw opened, fire swirling into a catastrophic vortex, a blast that could have erased Japonica itself.
"GO!" Klaus shouted.
Sofie spread her wings wide, golden-red fire engulfing the sky.
The Phoenix screamed through her, and she dove straight into the blast.
Her flames devoured the Demon's fire, consuming it, forcing it back into its throat.
The beast reeled and staggered.
Tatsuki was already in motion.
Her katana hummed, her Ryōki splitting reality itself.
She whispered through clenched teeth:"Dimensional Slash!"
A crimson rift tore across the Demon's spine, bending space and time, cutting its regeneration apart for one perfect second.
Klaus roared, his body glowing with the Yashariku spirit.
He sprinted forward, the Fushigiri raised high, every step heavier than thunder.
Ashborn bellowed inside him:"NOW! BRING DOWN THE CURTAIN ON IMMORTALITY!"
But the Demon lashed out, even in its stagger its claw was descending, ready to crush Klaus before he could reach.
Isshin moved. His broken body still faster than lightning.
"ARASHI CROSS!!"
Two strikes, impossibly fast, severed the claw mid-air. Blood and flame erupted.
"Go, boy!" Isshin roared.
Klaus leapt, higher than he ever had, higher than human limits.
Sofie's flames wrapped around him, guiding him.
Tatsuki's Ryōki surged, sharpening his blade beyond mortal comprehension.
Isshin's sacrifice cleared the path.
The Fushigiri glowed a cursed brilliance, a promise of final death.
Klaus screamed, every ounce of soul poured into the strike.
And he brought it down.
The blade cut through the Demon's skull, cleaving its core.
For a heartbeat, the world froze.
Then—
A shockwave erupted, black and red flames twisting into nothingness, the beast shrieking a final, horrific cry that shook mountains.
Its immortal body unraveled, burning away into ash that the wind carried into the void.
Silence.
The Demon of Hatred was no more.
Only the four of them remained breathing heavy, bloodied and scarred, yet alive.
Klaus fell to his knees, the Fushigiri still humming faintly in his grip.
Sofie caught him before he collapsed, her Phoenix armor fading, leaving her trembling but smiling.
Tatsuki's aura receded, her katana cracking slightly from the strain, but her eyes shone bright with relief.
Isshin exhaled, leaning on his Odachi.
His face was pale, sweat dripping, but his smirk hadn't faded.
"Hmph. You brats fought like hell."
He coughed violently, spitting blood, but still laughed. "Arashi… will live on… through you."
The sky above cleared, the fires fading, dawn breaking over japonica for the first time in what felt like centuries.
The Demon was gone.
---
The battlefield was quiet now.
The flames had died. The sky had cleared.
Only silence… and the sound of heavy, ragged breaths.
Isshin staggered once, then twice before his knees buckled.
He collapsed to the scorched earth.
"Grandpa!!" Tatsuki screamed, rushing to him. She fell to her knees, cradling his head gently in her lap.
Her tears streamed down her face, falling against his weathered cheeks.
Isshin coughed, his lips curved in that same wolfish grin.
"Tch… don't cry, girl. This old man ain't gonna die before he sees your marriage."
Even through her sobs, Tatsuki let out a shaky giggle. "Y-You idiot… that's not funny."
Isshin chuckled hoarsely, closing his eyes for a moment. "Hah… then it worked."
Sofie stepped forward, trembling. She turned her gaze inward.Phoenix… can you heal him? Please…
The flames within her stirred, the Phoenix's voice warm but hesitant.
"I'll try."
From her chest, light spilled forth.
The Phoenix emerged in a radiant, humanoid form, wings folding around it as it knelt beside Isshin's body.
Its eyes glowed with ancient fire as it studied the Sword Saint.
Minutes passed in silence, broken only by Tatsuki's frantic breaths.
Finally, the Phoenix's flames dimmed.
It whispered, almost in awe "…Incredible. This human… was dead not long ago. But his spirit fought long enough to end the fight."
Tatsuki's eyes went wide, her hands trembling as she shook Isshin's shoulder.
"No… no no no no no… don't say that!! Grandpa!! GRANDPA!!"
But Isshin didn't answer.
The grin still lingered on his face, as though he had left laughing.
"…No… please… don't go…" Tatsuki broke, sobbing uncontrollably, her cries echoing into the empty battlefield.
Klaus lowered his head, gripping the Fushigiri so tightly his knuckles turned white.
Sofie covered her mouth, tears streaming down her cheeks, her Phoenix standing silently beside her, its head bowed in respect.
The Sword Saint, Isshin Arashi , had breathed his last.
Not to disease, not to weakness.
But on the battlefield, as he had always wanted facing death with a grin.
And in his granddaughter's arms… his spirit finally rested.