Two figures stood on a stage. Silence enveloped the stands as they began to engage in combat. 

All that could be heard was the rhythmic clash of metal echoing through the hollow arena.

Among the two figures, one was a man with hair as black as night and green jewels for eyes.

The other was a woman with skin as pale as the highest moon, eyes bright and soothing with luxurious silvery chestnut hair. Their looks and performance captivated everyone in the stands.

Their fight was akin to a beautiful sonnet, a dance of clashing blades, creating a melodic rhythm that seemed to merge into a harmonious tune.

Both wore smiles on their faces as if they were dancing at a ball. Both wielding double-edged, balanced cross-guard swords—one silver and the other gray, adorned with cryptic runes that exuded an innate beauty. 

The figures clashed, retreated, and clashed again. Their swords entangled when they drew close, exchanging smiles before retreating again, their footsteps echoing throughout.

It was a mesmerizing display of beauty, reminiscent of swans gliding on a lake or doves soaring in the sky together. It held the rapt attention of the entire audience.

Fighting for what seemed like hours, the climax neared.

The gray sword found its mark, brushing against the girl's neck, its wielder's face touching hers. 

A hushed silence fell over the arena, and then a feminine figure broke that silence.

"You better win," she whispered before moving closer and stealing a kiss.

Luna blushed as she pulled back, her competitiveness giving way to affection.

Cain too blushed, losing his composure as everyone in the crowd seemed to grin at his embarrassment. This tournament became a show in multiple ways.

Raising her hands, Luna surrendered, and Cain was declared the winner.

"Cain wins and will move to the finals!" The announcer roared and the crowd erupted into applause and cheers, the arena filled with jubilant sounds of celebration that rang throughout the city.

…

In a locker room, Cain wiped the sweat from his forehead with a towel, while his master, John, grinned.

"So... when are you going to marry her?"

Cain paused, displeased. "Master, just stop."

John raised his hands like he was innocent. "What? I mean, she kissed you in front of everyone, and her parents will push for her to get involved with you. Or even more, they might demand you marry her. Of course, this is because you have such a powerful master with high status. Otherwise, they might try to kill you instead."

Cain frowned. "You're full of yourself."

John chuckled and left Cain alone with his thoughts. Though John had his own romantic troubles once, he didn't have them anymore.

He walked out of the locker room sulking, remembering his past failed romances.

Cain had no time to laugh at his master ruining his mood, the finals were about to begin! Cain had to clear his mind and head back to the stage.

 …

In the arena, a youth stood in the middle of the stone court, brought to the surface. Cain recognized it was Okvan, still wielding his sickle, looking pale and fatigued.

Cain stepped onto the stage, the crowd applauded before falling silent to listen to the announcer.

"Ladies and gentlemen, today is the day! The day to decide the winner of an event that happens once in a few centuries! Now, two remarkable individuals stand before us: Cain, the Emerald Butcher, and Okvan, the Reaper of the Uslavi family! Finally, let the battle commence!"

Like all these amateur battles played out. Cain and Okvan put all their strength into their legs to achieve inhuman speeds. 

They moved a few feet from their initial positions to clash. They attacked each other, waiting until each was in striking distance, well… least Okvan was.

He readied his sickle and sent it flying towards Cain, who was still closing in. 

The sickle passed by Cain but, under Okvan's control, it began to wrap around his opponent.

In response, the pommel of Cain's daggers glowed as he bashed them against the chains, watching them corrode and break under his prowess. 

Looking displeased, Okvan retrieved a vial containing an unknown foul liquid, just like in his fight with Hank.

Cain in kind, quickened his pace.

The emerald butcher swung his dagger at Okvan's vial. Okvan raised the chains and swiped them downward, catching Cain's dagger and trapping his hand.

With his teeth, Okvan uncapped the vial and poured its contents on the chains. Almost rattling, the chain began to react and turn to that similar-looking, rusted metal. The metallic material lost its luster as the rust spread like a disease.

Grimacing, Cain used his other dagger to free himself from Okvan's chains, leveraging his dagger against his flesh and gaining some distance.

Despite the disadvantage, Cain was not worried. He knew this was Okvan's trump card.

Using the knowledge he learned from John, he knew tiny runes were running through the chains, dormant until an activator triggered them, turning the weapon alive.

John had informed Cain the liquid Okvan used to be the activator for the runes. The weapon was a family heirloom.

Armed with this knowledge, Cain had an edge; he knew more about his opponent than they knew about him. With a clear strategy to win, Cain kept his confidence.

'All I have to do is break the runes. Simple right?'

Breaking the runes was a challenging task, with Okvan's weapon composed of intricate ones. However, if Cain could somehow shatter a single rune in the intricate web, the weapon would break from instability.

But this was a dilemma; he knew how to win but not how to achieve it. He lacked knowledge of how to break or remove the runes, a significant gap in his strategy.

However, he did understand how to defeat diseases—by discovering their weaknesses or overpowering them. Though Cain didn't know the specific disease within the weapon, he could overpower it by sacrificing his weapons. That was his best bet, his chance.

He formulated a plan in his head while Okvan relentlessly attacked, throwing everything at him. 

Cain, nimble as ever, dodged again and again with grace. He wasn't so skilled in fighting but he was good at reacting and dodging, to say the least. 

He completed his plan and put one of his daggers away, eliciting cheers from the crowd.

Cain then… allowed himself to be attacked. He let the chains and sickle graze him while he used his remaining dagger to strike the chain.

It became a battle of stamina, Okvan now had all the initiative. Cain had let him win?!

Initially, this favor held true as he wore down Cain. However, after more than 5 whole minutes! Okvan realized something unsettling—Cain seemed unaffected, even more energetic than before.

Upon closer inspection, one could see Cain's wounds healing. He appeared numb to pain as if he were a zombie.

'Shit, he has augmented his body!' Okvan, astonished by Cain's zombie-like attributes, learned the unsettling truth. 

The sad fact of the matter was that Okvan himself had not been augmented, one of his only disadvantages. 

Cain chuckled to himself, he finally found the weak link in the chain and was ready to execute his plan. He retrieved the dagger he had put away and charged at Okvan one final time, his figure becoming hazy. 

Okvan, desperate, launched his chains, but Cain evaded each strike. Reaching his fatigued opponent, Cain realized he could have overpowered Okvan all this time.

He shook his head, realizing his own mistake. 'I'm an idiot. All he has is the weapon… that's it.'

Cain had overestimated his opponent, but he won nevertheless. With ease, he knocked the weapon out of Okvan's hand, after this he had to reevaluate his intelligence.

Nonetheless, he was relieved that he hadn't provoked Okvan's family by destroying their weapon.

With Okvan at his mercy, Cain was declared the victor, prompting an ecstatic reaction from the crowd. 

"The winner of the tournament hosted by the Union itself! Is Cain, the Emerald Butcher!"

'They don't have to call me by that nickname...' 

It was a good day, the day 'Cain, the Emerald Butcher' was cheered so many times it drowned out all other noise in the arena at the Plague Doctor school of Nevarus.

…

"Sir, are you ready to enter the vault?" The same attendant as before was leading Cain to the vault. Again, he was standing before that cold steel vault door.

"Yes"

Hearing the creaking metal, and the smell of ancient stone. Cain felt his heartbeat fasten as he once again entered the vault once more.

But he had no time to take it in, this time he had a goal. 

He headed towards the documents, embarking on a desperate search. He looked through document after document as he ventured closer to the dimly illuminated area containing more ancient items.

Scrolling past the many preserved laminated papers, he quickly read off the titles in his mind. 

'Micro-organisms with consciousness'

'Plague plants'

'Ways to infect through the air'

'Does Grade 5 exist? Answering unanswered questions'

Thousands of research documents contained information on various topics, but none held the answers Cain sought. Time was running out, as he had only five hours, more than last time but still not enough.

One hour passed... two hours... three hours.

'Biography of the Plague Demon'

'The Maddening Red'

'Theory of Dimensional Space'

'Multiverse Theory'

Cain's hope began to wane as he neared the end of the documents.

Yet, as his hope faded, his gaze landed on a dusty, worn book half-hidden behind a pile of scrolls, as if it didn't want to be found. The cryptic title glimmered in the lamplight. It wasn't a research document but books and documents were virtually the same.

The book had a peeling velvet cover with its title gilded in gold fabric. As he brushed the dust off the cover, he could make out the title. 

'Speculations Towards Augmentation'

Cain felt a subtle pressure like this was what he had been looking for. He opened it up with trembling hands and began pursuing its contents.

'This is it! I found it!' Tears of joy began to build up in his eyes, making him unable to read all the contents. 

From what he could tell throughout all the watery haze, was that the book detailed the author's speculations on how augmentation worked and whether it was truly 'augmentation'.

It explained that augmentation involved using bacteria or viruses to strengthen the body, akin to how plague doctors manipulated diseases for different purposes. 

But augmentation could be used by anyone, the disease did not need control as it naturally worked throughout the body, acting on its biological 'programming' set by the serum's creator. 

However, the book suggested that true augmentation required permanent changes to the body, almost like evolution.

It outlined various theories for achieving this, all of which required extensive practical research. 

For this to work, the body would have to withstand the process without succumbing to infection, a baptism if you will. 

However, this specific way of augmenting required the viruses to freely augment cells without killing them. This would require nanoengineering never seen before. 

'To program a virus and change its nature against itself….this guy's insane. But I long had similar thoughts.'

While the book provided insights into changing the viruses to fit these needs, it didn't delve into how the person undergoing the process could survive. Fortunately, Cain had a solution in mind—the Animum virus.