A Wild Last Boss Appeared

Gale Volcano. Standing at one thousand meters above sea level, it lies twenty kilometers away from Suvell. Although reportedly an active volcano, it has laid dormant for centuries past.

At the foot of the natural monument stood an equally impressive castle, which was teeming with monsters. However, Aries' titanic form was nowhere to be seen, and by no means could his huge build enter the narrow confines of the fortress. It was but an object of pride, as the throne sat empty in the center of the estate.

But if Aries truly wished, entering the castle was a simple matter. Thanks to his tamer's skills, the ram was granted a temporary humanoid form. With it, assuming the throne would be a walk in the park. However, Aries had no intention of taking a human form. In his crazed hunger for revenge, he was sure it would be an unsightly appearance. And he did not dare to taint the elegant form handed down by his lord and master… for the span of two centuries, not once had Aries walked on two legs.

"Aries"

A voice called out to the ancient familiar lying beside the castle. It was the clear voice of a young boy, towards which Aries shot a sharp gaze of annoyance. The lad barely reached five feet, a size that Aries' hundred meter form could easily overlook. Yet, he had the nerve to grin at the ram. Aries exhaled, sighing through his nose.

"What do you want?"

"Oho? May I not speak with you when there is nothing I desire?"

Except for the blue hue of the boy's skin, he looked almost human. That is, if you ignored the reversed colors of his pupils and his whites. And, oh, the fangs that peeked out from under his upper lip, which proved him completely inhuman. In reality, he was of a race of people that drove mankind to a corner—a member of demonkind.

"First, let me congratulate you. With this, Levia has greatly weakened… I'm sure victory will be yours on your next attack."

"…That goes without saying."

"Then why have you slept for days on end without making a single move? Just a little more and Suvell will crumble. What are you waiting for?"

As if he was an old friend, the demon boy offered an outlet to Aries' worries. However, the dangerous glint in his eyes said otherwise. Despite his caring words, his eyes remained devoid of emotion.

"No, not just this time. For these past few years, you could have crushed Suvell whenever you wanted. Yet you've left them unscathed for years. Why is that?"

"…"

"Don't tell me you're hesitating, are you? They're the ones who betrayed your master."

"…I haven't forgotten."

Aries was wavering. That was the indisputable truth. But it wasn't about killing the seven heroes, no. If they had been average warriors, he would have slaughtered them without a second thought. But that was where the problem lied. Each hero played a pivotal role to humanity's defenses. With the collapse of every sequential nation, demonkind took one step closer to world domination.

And that was something his lord would never wish upon Midgard. As someone who hoped most to rid mankind of its fear of demons, the Black-Winged Overlord was not one to topple nations for some petty revenge. And a revenge that tainted his lord's memory would be no revenge at all. But even then…

He would not forget—He refused to forget the fleeting moments he spent with his precious lord and savior. And the incredible rage he felt towards those who stole her warmth away from him.

"I don't need you to tell me… I will kill Megrez. I was only waiting for my wounds to heal."

"I see, I see. I'm glad to hear it. So I'm guessing you're raring to go?"

"…Yeah. I can barely contain myself."

He had his doubts. However, as long as Megrez—no, even one of those seven "heroes" remained, Aries will not have avenged his master. Whether his actions led to the world's collapse was none of his concern. This was the only way he could appease the rage and grief from having his lord stolen away.

Giving into rage once more, Aries lifted his enormous frame from the ground. This time around, Levia would not survive the encounter. Nevermind Megrez, who was far from the peak of his power.

"Well, no sense in waiting. My monsters have been ready. Of course, they're nothing like last time's fodder. I've got monsters and wyverns who've all broken level 80. Not even that sword saint will last ten minutes against this bunch."

"…Sounds like a bunch of small fry to me."

"Oh be a bit more lenient, will you? Most all monsters are weak compared to you."

The horde's presence made little difference to a monster of Aries' caliber. Over the past two centuries, mankind wasn't the only one to lose their once great fighting prowess.

Despite demonkind's claim to victory, by no means was their kind free from casualties. While mankind lost their heroes to war, the greatest of demon nobles perished in battle. Likewise, powerful monsters were exploited as tools of war, driving many to the brink of extinction.

The odds had been just as likely to tip in mankind's favor as it was to demonkind. Both sides of the war had an even chance at victory. And that… that was unforgivable.

If only his liege had lived to fight the war, victory would not have been a prospect.

It would have been a certainty.

The demon filth would have been purged from Midgard's soil, and the world born anew, free from fear of their kind. It would only be right.

So who was to blame for mankind's demise? Who had beckoned to the world's ruin? Was it the gods, who abandoned humanity to its downfall? Was it his lord, who unified all of mankind? Or was it the simple murderers, who were worshiped as heroes, and still lived unpunished to this day?

He would kill them.

His only concern was…

The anomaly in the red overcoat. He reminded Aries of his late master, and it wrought an odd mixture of fear and hope in Aries' broken heart.

・・・

"Heh… Suvell will finally fall to its ruin. Surely the Demon King will rejoice! Another of the foolish seven heroes will soon meet his maker."

The demon boy—one of the Demon King's "Seven Ferii"—chuckled at his impending success. At last, Mars could present the Demon King with the head of a hero. With this, the other six would realize how worthy he was to be the King's aide.

Two centuries had lapsed since the age of heroes, and the devious masterminds of the time had lost their lives. It was about time for new leaders of demonkind to rise to glory and the Seven Ferii were assembled under that mindset. However, they lacked actual achievements to back their positions. But this—this was it. With this final victory, he would earn the Demon King's trust.

At first, the conquest of Suvell seemed all too ambitious. To say nothing of Megrez himself, Levia posed quite the challenge. "Difficult" was a generous word when it came to finding someone willing to challenge a tireless water dragon impervious to physical attacks. The addition of Levia's regenerative powers and titanic size was of little help.

However, Lady Luck stood firmly by his side. The moment Mars found Aries by Gale Volcano, he was sure her holiness Alovenas was watching from above. So he invested years into nourishing a desire for revenge in a wavering Aries, which was by no means an easy task.

But soon, he would be rewarded for his hard work. To convince a pillar of the Twelve Heavenly Stars to turn on his former allies… How devious! How cunning!

Show me, vengeful ram! The face of despair as mankind falls to ruin!

"What bothers me is that red overcoat… Aries was off-guard, but anyone who can send Aries flying is nothing to sneeze at…"

Well, Mars was sure the guy was no match for Aries. But with Levia's and Megrez's help, he was no longer so confident of the ram's victory. While he did have the army of monsters, he wasn't sure if they would help against such monsters of opponents.

"Well, worst case scenario, I'll just make an appearance myself."

Mars crossed his arms and watched the horde march for the war front. Surely, he had the upper hand. As long as he proceeded carefully, victory was certain. He could almost see Megrez's despairing expression as his kingdom crumbled around him.

Soon, he would become an object of envy to his fellow Ferii. Good things truly did come to those who wait. Mars smiled at the thought—

—And hundreds of monsters were suddenly sent flying, wiping the smug grin right off his face.

"…The-the fuck!?"

Mars leaned out of the castle window for a better look. What? What just happened? Could Megrez have come himself? With a demon's excellent eyesight, he scanned the point of impact. And then he saw it.

Approaching on foot was a figure in that dreaded crimson overcoat.

"That's…!"

It was that fucking anomaly again! How dare he stand in his way! No… he needed to calm down. This was a chance—yes, a chance! If he took care of that red bitch now, Megrez and Levia would have to hold the front alone. If worse came to worst, Mars, Aries, and a couple higher ranked monsters could conquer Suvell themselves. It didn't matter how many sacrifices he had to make. He would take this fucker down.

"Don't falter! There's only one enemy!"

Mars barked words of encouragement, spurring his army into action. Monsters surged forward to face a single enemy. No matter how strong a foe, he was, in the end, mortal. No amount of strength could overcome the might of overwhelming numbers.

Or so he thought as tens—no, hundreds of swords tore his army to shreds. Scores of monsters fell victim to the blades, yet not a single one came close to the crimson warrior. Even as the corpses reached the hundreds, his horde inched no closer to their foe.

Yet, the furious onslaught showed no signs of slowing. It wasn't until the army recoiled did the warrior pause to admire his handiwork. More than five hundred corpses laid at his feet, a tribute to strength that surpassed the might of numbers.

"…who the fuck…"

Absurd… This was absurd! It was as if the heroes of legend had returned! Perhaps, was he another of the seven heroes? No… the Heavenly King was renown for his hatred of mana, and the Vampire Princess was not one to help others.

He was not a hero of the rebellion, yet the red warrior was a force to be reckoned with. Seeing his attacks as both a waste of effort and soldiers, Mars ordered his army to withdraw. He would dance with the warrior himself.

"…A demonkin, huh?"

"It is as you say. And you are? To think that warriors of your caliber still existed…" Mars said, as he unsheathed a pair of daggers.

On his right, he held a blade of fire. On his left, he gripped a blade of ice. Ice to seal his enemies' movements and fire to burn them to a charred corpse. Such a sudden change in temperature rendered all things brittle to the touch, fit for Mars to crush under his heel like an aluminum can.

"You've done well to come so far, but your winning streak has come to an end. You see, those who oppose the Demon King don't live long. You only have yourself to blame for meeting such an unfortunate end."

Mars lunged forward. Using his body's light build, the demon reached speeds difficult for the eye to follow. Each pivot left yet another afterimage as he froze his enemy, restricting their movements. This was the source of his pride, a technique not a single victim had survived. It was his ultimate, sure-kill attack.

"Behold! The secret technique of one of the Seven Ferii! The Fire-Ice Doubleplay! As I rob you of your mobility than your life, it is the last, greatest thing you'll witness. Raging hellfires shall send you to your death! But do not fret. The pain will only last an instant, and that is the last mercy I grant you. Rather, you should be grateful! Grateful for the salvation I grant you! Life is but a struggle for—"

"Shut up."

—the next moment, Mars was knocked into the air, his mind unable to register what had transpired. He understood but one thing: the unfathomable power that sent him flying.

"…No…Way…"

Something ruptured inside him, and blood gushed from his mouth. What… just happened? Even the seven heroes could not thrash him so…

—Mars' eyes widened in realization. Of the five hundred monsters he had thrown at the warrior, not a single one was dead! While unconscious, none suffered from fatal wounds. That meant the crimson warrior had the leeway to hold back against these overwhelming numbers. Not only were the transmuted blades dulled, he made sure to miss every vital point!

"Wh-who… the fuck… are you…"

As if to answer his inquiry, jet-black wings entered his fading field of vision. Mars could only stare in awe as they unfurled to their full span, revealing ruby eyes and locks of golden hair. She was too beautiful a bringer of death and too lovely a ruthless overlord. She was without a doubt…

"Ru… Ruphas… Ruphas Mafahl…!?"

Standing before him was the black-winged overlord even the Demon King so reluctantly feared. And Mars knew—that he had challenged the impossible.

・