The underground storage room shook violently as gunfire and roars echoed endlessly through the collapsing railway tunnels. Concrete continued falling from the ceiling while steam exploded from broken pipes across the battlefield. The Apex Mutation roared furiously in the center of the chaos while black blood covered its constantly evolving body. One damaged glowing eye stared directly toward the group now with pure murderous rage.

Yuna stood near the broken ceiling entrance above while firing her assault rifle nonstop into the creature’s chest. Empty bullet casings scattered across the ground around her feet while her red hair moved wildly under the flickering emergency lights. Beside her, Kaede calmly fired arrows downward one after another with terrifying precision despite the collapsing environment around them.

Meanwhile Reina moved through the battlefield like a storm.Her dual combat blades flashed repeatedly across the mutation’s body while she dodged every counterattack with frightening skill, And in the middle of all that chaos—Airi’s eyes remained locked entirely on Arata.

"...You’re injured again," she whispered softly.

Even through the battle, Even through the noise, Her concern reached him clearly.

Akari quietly noticed that immediately.And once again—That strange uncomfortable feeling returned inside her chest.

The mutation roared violently before smashing its claw toward Reina. She barely dodged backward while the attack destroyed half the storage room wall behind her instantly.

"THIS THING IS CHEATING!" Yuna shouted while reloading quickly.

"It evolved three times already!" Reina yelled back.

"That’s biologically illegal!"

Arata moved instantly before the creature attacked again. His blade flashed across the darkness while his newly awakened speed skill activated automatically. For one brief second, even the mutation lost sight of him.

CRACK!!

A deep slash tore directly across the monster’s chest while black blood exploded everywhere.

The creature screamed furiously, Akari stared silently again.Because every time Arata fought now—He looked less human, Not emotionally, Physically, Faster reflexes, Sharper instincts.

Movement impossible for normal people, The system flickered rapidly before him.

[Instinct Acceleration Active]

[Physical Output Increasing]

[Warning: Overuse May Damage Host Body]

"...Wonderful," Arata muttered quietly.

Akari immediately noticed his expression. "What?"

"Nothing important."

"That answer is suspicious."

"We have a giant murder monster currently."

"That doesn’t make you less suspicious!"

The mutation suddenly rushed toward Yuna above the ceiling opening, Too fast, Her eyes widened immediately, Before anyone else could react—Arata appeared directly beside her instantly before blocking the creature’s claw midair.

BOOOOOOM!!

The impact shattered portions of the upper tunnel floor while shockwaves spread throughout the underground structure.

Yuna stared at him silently afterward.

"...You really have a hero complex."

"Probably."

"You disappeared underground with another girl for hours and came back even more attractive somehow." Yuna looked genuinely offended. "That feels unfair."

Akari blinked slowly, Then immediately looked toward Yuna.

"...Wait."

Yuna narrowed her eyes instantly. "...What?"

Akari slowly pointed between both of them dramatically, "There’s definitely tension here."

Arata looked exhausted already. "...Please not now."

"Oh this is absolutely now," Yuna replied immediately.

The mutation roared furiously between them.

Nobody cared for one second.Even Reina looked interested suddenly while dodging infected nearby.

Kaede calmly fired another arrow into the mutation before speaking softly. "...This conversation does seem emotionally complicated."

"THANK YOU," Akari replied instantly.Arata stared blankly at the ceiling briefly.

"...I miss when my problems were only zombies."

The mutation attacked again violently.This time everyone moved together instantly.

Reina slashed across the creature’s legs while Kaede’s arrows pierced its shoulder repeatedly. Yuna unloaded rifle fire into the damaged eye while Arata attacked directly from the front.

Akari quickly joined beside him again with the baseball bat.Yuna noticed immediately, Her eyes narrowed slightly.

"...Why are YOU always beside him specifically?"

Akari blinked. "...Because we nearly died together underground?"

"That answer somehow annoys me."

"That sounds personal."

"It’s absolutely personal."

"YOU TWO!" Reina shouted while dodging debris. "FOCUS BEFORE WE ALL DIE!"

The mutation smashed both claws into the ground violently.

BOOOOOOOM!!

The floor beneath everyone cracked instantly.

Massive fractures spread throughout the storage room while nearby walls began collapsing rapidly now.

Airi’s expression changed immediately. "...The entire underground structure is failing."

"That sounds bad," Yuna replied.

"That means RUN," Reina corrected instantly.

The mutation roared again before charging directly toward the group one final time.

Arata’s eyes narrowed.

"We finish it here."

Everyone froze briefly, Because of his voice.

Cold, Sharp, Certain.

The atmosphere around him felt completely different now.Even Yuna noticed it immediately.

"...Arata?"

He slowly raised his blade while black blood dripped from countless injuries across his body. Despite exhaustion, despite pain, despite barely standing—His eyes remained calm, Dangerously calm.

The system flickered violently.

[Combat Synchronization: 63%]

[Potential Evolution Path Detected]

[Warning: Emotional Stability Declining]

Arata ignored all of it, The mutation charged.

And Arata moved, Faster than before.

His body blurred through the collapsing room while sparks exploded behind every step. The creature attacked wildly but failed hitting him even once now.

Slash after slash tore through the mutation’s body instantly, Black blood exploded everywhere.

The creature screamed repeatedly while stumbling backward under the relentless assault.

Akari watched silently, So did everyone else.

Because right now—Arata looked terrifying.

Not like a survivor anymore.Like something adapting to the apocalypse itself.

The mutation roared furiously before attempting one final desperate attack toward Airi.

Too late, Arata appeared directly in front of it.

His blade flashed once, Silence followed immediately afterward.

Then— CRACK. A massive slash split directly through the mutation’s upper body.The monster froze completely.

Black blood slowly poured from the wound.

Then finally—The Apex Mutation collapsed.

The entire underground room became silent afterward, Only heavy breathing remained.

Only collapsing debris, Only flickering emergency lights, The monster was finally dead, Everyone stared silently for several seconds.Then Yuna suddenly raised both hands dramatically.

"WE’RE ALIVE!"

Reina immediately sighed deeply before sitting against nearby rubble. "I genuinely thought we were dying underground."

Kaede calmly lowered her bow afterward. "...Same."

Meanwhile Airi immediately rushed toward Arata.

"Your injuries—"Before she could finish—The underground ceiling cracked loudly again.

Everyone looked upward instantly, Huge sections of concrete began collapsing rapidly now, Arata grabbed Airi’s wrist immediately.

"We move. Now."

The entire railway structure started collapsing around them afterward.Everyone sprinted through the maintenance tunnels while debris crashed endlessly behind them. Dust filled the air while alarms echoed throughout the underground station again.

Akari ran beside Arata while gripping the baseball bat tightly, Yuna noticed that too, Again.And somehow—That irritated her more every minute.The tunnels shook violently while chunks of ceiling collapsed everywhere around them.

"LEFT!" Reina shouted suddenly.

Everyone turned instantly moments before the tunnel behind them collapsed completely.

BOOOOOOOOM!!

The shockwave nearly threw them forward.

Airi stumbled slightly afterward, Arata caught her automatically, Akari stared silently at that.

Then immediately looked away afterward, Annoyed, Which made absolutely no sense.

Yuna noticed both reactions instantly, Her eyes narrowed dangerously.

"...Interesting."

Arata immediately sensed disaster approaching emotionally.

"...Please don’t."

"Don’t what?"

"That tone."

"What tone?"

"The dangerous one."

"I don’t know what you mean."

Reina immediately whispered toward Kaede nearby. "...He’s doomed."

Kaede quietly nodded. "...Extremely doomed."

The group finally reached an old emergency railway exit leading upward toward the surface. Cold night air rushed through the broken stairway while moonlight faintly illuminated the ruined city above.

Everyone slowly emerged from underground afterward.And for the first time in hours—Fresh air reached their lungs again.The city looked horrifying.

Fires burned across distant buildings while infected screams echoed through the ruined streets endlessly. Smoke covered portions of the night sky while military helicopters moved far above the city occasionally.

But somehow—Compared to underground hell—This felt peaceful.Yuna immediately collapsed dramatically onto the road afterward. "I’m never going underground again."

Reina sat nearby while breathing heavily. "...Agreed."

Kaede quietly leaned against a destroyed car while checking remaining arrows.

Meanwhile Airi carefully examined Arata’s injuries under moonlight with visible concern.

"You pushed yourself too hard again."

"I’m fine."

"You’re absolutely not."

Akari silently watched them nearby.

Again—That uncomfortable feeling returned.

Yuna noticed instantly, And suddenly smiled.

Dangerously.

"Ohhhhh."

Akari blinked slightly. "...What?"

Yuna slowly stood afterward before walking closer toward her.

"You like him."

Silence.

Akari stared at her blankly, "...What?"

Yuna pointed dramatically toward Arata. "You like HIM."

"I literally met him today."

"And?"

"And that’s insane."

Yuna crossed her arms proudly. "Apocalypse emotions develop faster."

"That’s not scientific."

"Neither are zombies."

"...Fair point."

Reina suddenly joined the conversation while eating emergency snacks somehow. "...Honestly the chemistry was obvious."

Akari looked betrayed instantly. "YOU TOO?!"

Kaede calmly nodded nearby. "...You stand closer to him unconsciously."

Akari froze, "...Excuse me?"

"And you look at him constantly," Reina added helpfully.

Akari immediately looked horrified.Then all three girls slowly turned toward Yuna.

Silence followed, Then Reina blinked slightly. "...Wait. You like him too."

Yuna froze instantly.

"...What?"

Kaede calmly spoke again. "Your jealousy became noticeable approximately twenty minutes ago."

Yuna looked personally attacked.Meanwhile nearby—Arata sat quietly against broken concrete while completely ignoring the ongoing emotional disaster behind him.

Airi carefully cleaned the injuries across his arms silently.

"You’re lucky none of the wounds became infected."

"Yeah."

Airi looked at him quietly afterward.

"...I was worried."

Arata slowly glanced toward her.Moonlight reflected softly across Airi’s silver hair while cold night wind moved gently through the destroyed streets around them.

"...Sorry."

Airi smiled faintly afterward. "You always apologize after nearly dying."

"...Habit."

"You should stop that habit."

For one brief second—The atmosphere between them became soft, Warm,Comfortable.

Then suddenly— "ARATA!"

Yuna’s dramatic voice shattered the peaceful moment instantly.

He looked exhausted already. "...What now?"

Yuna immediately pointed toward Akari dramatically.

"She likes you."

Akari’s soul visibly left her body.

"...WHAT?!"

Reina immediately started laughing nearby while Kaede quietly looked away pretending innocence.

Arata blinked slowly, Then looked toward Akari.Akari looked ready to commit murder.

"...I’m going back underground," she whispered.

Yuna pointed accusingly again. "SEE?! Emotional avoidance!"

"I WILL HIT YOU WITH THIS BAT."

"VIOLENCE CONFIRMS FEELINGS!"

Arata quietly covered his face with one hand.

"...The apocalypse was a mistake."

For the first time in years—Real laughter escaped him afterward, Small, Tired, But real. And everyone froze instantly after hearing it.

Because somehow—Hearing Arata genuinely laugh felt more shocking than fighting monsters all night.

Silence followed briefly.Then Airi smiled softly.

Yuna stared dramatically, Reina looked confused, Kaede blinked slowly, Meanwhile Akari simply stared at him quietly.Because suddenly—She understood something terrifying.That sound—Made her happier than it should’ve.