Lack of Killer Instinct

"Silence enveloped the chamber, broken only by the echoing clash of swords. The Fallen, draped in ominous armor and wielding a colossal dark sword, materialized before Shuuta with unsettling ease, courtesy of his teleportation skill.

Shuuta, fueled by determination, parried the oncoming blow with all his strength. The collision of their swords emitted dazzling sparks, casting a momentary glow on their intense faces.

"Yo, kid. Been a while since I've met anyone worth my time. I was itching for some blood," the Fallen declared with a malevolent laughter, casting an eerie atmosphere.

"You're a Mystic, aren't you? What are you doing here? This is supposed to be Master Iho's dungeon!" Shuuta questioned, eyeing his opponent cautiously.

"Ehhh? What are you blabbering about? This is Hiroyama's maximum prison. A dungeon forgotten by time," the Fallen retorted, his eyes reflecting both sorrow and rage as he swiftly overpowered Shuuta, disrupting his stance.

"Watch out!" Hikaru intervened, pulling Shuuta to safety with his serpentine ally.

"T-thanks..." Shuuta winced in pain, revealing the severity of his injuries inflicted by the Fallen's ferocious assault.

Hikaru, assessing the situation, wondered, 'How strong is this opponent? Do we stand a chance?' His gaze bore into the armored knight.

"W-who are you?" Shuuta inquired through gritted teeth.

"Me? I'm here to end both of you. Why bother knowing more?" The Fallen lunged at Shuuta, his massive sword ready to strike.

"I won't let you!" Hikaru roared, unleashing his snakes in a futile attempt to protect Shuuta.

"Heh." The Fallen effortlessly teleported Hikaru away, leaving Shuuta vulnerable.

"[Devour Magic: Devour Shockwave!]" Shuuta erupted, creating an explosive burst of Devour mana that caught the Fallen off guard, revealing his true face.

"..!" Shuuta's shock was palpable; the Mystic before him bore the scars of time, with a face split in half and a grisly appearance.

"You're dead…" Shuuta declared, the revelation sinking in.

Hikaru, horrified by the sight, rushed to Shuuta's aid, witnessing a level of brutality beyond expectation.

"Oh, now you've done it. I'm afraid you can't leave this dungeon alive." The Fallen's menacing aura intensified, shrouding them in a malevolent force—a concoction of rage and bloodthirst that choked Shuuta.

The Fallen's gaze, sharp as a blade, instilled a sense of dread. Shuuta faced a true threat, a demonic aura reminiscent of a malevolent lord.

Gritting his teeth, shaking but resolute, Shuuta vowed, "I will rescue Hanako. I will defeat you!" Blood dripped from his bitten lips as he steeled himself.

"I was created for one purpose: to kill. I've been slaughtering prisoners for centuries. You're just another drop in the ocean," the Fallen revealed, materializing his dark sword with a sinister grin.

Shuuta, exhaling deeply, shouted, "Don't get in my way, Hikaru! This battle is mine alone!"

"What?! Are you crazy?! You're going to die!" Hikaru protested, ready to intervene.

"Stop right there, Hikaru-boy. Shuuta has chosen to battle alone. This fight is for his honor. Do not interfere," Granny Iho's voice echoed in Hikaru's mind.

Hikaru hesitated but ultimately complied, watching intently as Shuuta faced a foe leagues beyond their capabilities.

"Don't you die, Shuuta! Or I'll kill you," Hikaru declared, his gaze a mix of concern and determination.

Sparks flew as metal clashed, and Shuuta, undeterred by his injuries, initiated his plan with a resolute cry, "[Devourer's Mark!]" The battlefield crackled with impending confrontation."

"W-what? What's happening... I feel weaker." The Fallen sensed an increasing weight on his body, as if an unseen force was draining his very essence.

His mana reserves dwindled rapidly, devoured by a malevolent entity. Helplessly, he watched his own mana dissipate before his eyes, the sinister process unfolding with cruel deliberation.

The Fallen's eyes bore into Shuuta with scorching rage, and his massive sword blurred through Shuuta's vision. To Shuuta's astonishment, the onslaught didn't seem to weaken the Fallen physically.

Shuuta, quick on his feet, parried the colossal greatsword by slamming his katana sideways and gripping it with both hands. A guttural growl escaped him as he struggled to resist the overpowering force attempting to empower the Fallen.

"You, this is the end for you. Your limitations will be your downfall! Kid!" The Fallen opened a rift behind and in front of Shuuta, unleashing a deadly attack, "[Fallen Angel's Tears!]"

"…!" Shuuta's eyes widened in sheer shock as the greatsword pierced his chest, leaving a trail of crimson on the ground.

"Ghhht!" Holding his wounded chest, Shuuta staggered back with a colossal leap, displaying remarkable resilience.

"Resilient little morsel, but..." The Fallen mused, his words hanging in the air.

"What!?" Shuuta, still recovering from the brutal strike, stared in disbelief as rifts painted the room.

"Even with my [Devourer's Mark], he's this powerful? I…I…what can I do?" Shuuta questioned his own abilities, uncertainty etched across his face.

Granny Iho observed the scene with a shiver, sensing an ominous anomaly. "Kentaro-boy…" She turned her gaze towards Kentaro.

"Shuuta... don't die, dumbass." Hikaru, torn between his impulse to intervene and respect for Shuuta's decision, clenched his teeth, blood trickling from his mouth.

"Shuuta-kun... hang in there." Yuri's voice, filled with concern, reached Shuuta.

"Shuuta-sama… beat him into a pulp! You are the Demon King! Conquer your enemies and bring them to your knees!" Kakoyo radiated a fiery killing intent, urging Shuuta to triumph.

Noara frowned at Kakoyo's intensity. "Father…what should I do? How do I beat Spatial Magic?" He muttered a healing spell, but its effectiveness was limited due to his lack of proficiency.

Suddenly, a voice echoed in Shuuta's mind. "Shuuta, I'll give you advice. Advice that will make you unpredictable and a dangerous opponent. But first… [King Magic: Ashtarot's Sovereign!]" The Demon King's spell froze time, leaving everyone in suspended animation.

"F-father?" Shuuta, bewildered, found himself in a blank white space, facing the imposing figure of the Demon King.

"What do you know about Magic?" Abaddon asked, pressing Shuuta for an answer.

"I don't know," Shuuta replied, his face betraying an aloof demeanor.

"…Ehhhh….for real?"

"For real, for real."

"You're telling me… that you've been fighting monsters and enemies without even knowing!?" Abaddon, now the shocked one, comically hit Shuuta's head in disbelief.

"Idiot! Are all your Masters useless?! This is the most basic knowledge to have, but it is also the most important." Abaddon scolded his son, revealing the gravity of Shuuta's ignorance.

"Go on…"

Abaddon sighed and began a crucial lesson. "Listen up, Magical Energy, or Mana, is the energy of life itself, flowing throughout all of us. Even humans have Mana; they just don't know how to tap into it."

"O-okay? Now I know..." Shuuta nervously responded.

'In reality, there are more forms of energy. [Magical Energy], [Physical Energy], and [Spiritual Energy]. In order to cast 'skills,' you must master all energies. You may be strong physically, but your lack of a killer instinct weakens your blows and narrows your mind in combat." Abaddon imparted a crucial lesson on the essence of combat.

"K-killer instinct? But I don't kill! I only fight to protect those I love! I-"

"Silence! You're just a kid who stumbled upon powers. You know nothing about this world, the pain of losing more than you think. The pain of losing a loved one." Abaddon's face darkened with sorrow as he shared a painful memory.

Shuuta envisioned Hanako's smiling face and felt a shared sense of powerlessness. "Shuuta. I don't want to lose you too. You're the only thing in the world that I have left. I want you to survive, but right now, your principles and morals might kill you in the end. Let me show you how to be a Mystic truly." Abaddon's serious gaze conveyed a potent aura of killing intent.

"Remember this feeling."

Shuuta suddenly found himself drenched in a cold sweat, his entire being quivering like a leaf in the wind. A petrifying sense gripped him, his blood felt like it was freezing, and the veins in his body seemed to be clogged with an overwhelming fear.

His eyes widened with horror as the once-white room transformed into a macabre sea of blood. The sheer mana pressure emanating from Abaddon struck him like a tidal wave, rendering him speechless. At that moment, Shuuta felt like an ant standing next to a planet, and a nervous laugh escaped him as he teetered on the edge of losing his sanity.

Abaddon, without uttering a word or making a single motion, locked eyes with his son, an intense gaze that cut through Shuuta's very soul. "[Mana Release: King of all Kings]" Abaddon's hand rose before Shuuta's face, elevating the mana pressure even higher.

"…!" Shuuta, slow to react, braced himself for an imminent blast from his father. 'Shit!' echoed in his mind as tension reached its peak.

Tap*

However, instead of an onslaught, Shuuta felt a tap on his shoulder. Abaddon's voice resonated in the air, piercing the eerie silence. "It seems you've lost your cool. This power level is my bare minimum. All my Demon Generals can reach this level, and not even those Heavenly Commanders are strong enough to beat them. And you, my son, are not even strong enough to beat a mere Heavenly Commander… one that has no mana whatsoever."

As Abaddon scolded, he placed his hand on Shuuta's shoulder, offering both guidance and reassurance. "Do not fret. You have the potential to be the next Demon King. You are a hybrid, a Mystic and a Demon, not to mention my son! I believe in you since the day you were born. I believed in your mother's decision and in your existence. I know I took too long to say this, but…" Abaddon's expression softened, and he delivered the most sincere smile Shuuta had ever seen — pure and filled with love, invoking warmth and happiness.

"I love you, son, and remember that your mother also loves you too. We would never let you die!" Abaddon shifted to an aloof demeanor, but the sentiment lingered.

"But I already died once," Shuuta retorted, an undertone of anger in his words. Yet, he felt a sense of relaxation, a comforting familiarity, as if his mother's presence enveloped him.

"Thanks, Dad. I wish there was a way to thank Mom…"

Abaddon tenderly caressed Shuuta's head and smiled. "She already knows, Shuuta. Let's focus on training for now. That ghost Hanako must be concerned about you, so hurry up and become stronger than a Heavenly Commander." Abaddon stepped back, crossing his arms with determination.

"Let's begin."

"Yeah! Father!" Shuuta responded with newfound resolve.