"Yin, current mana level?"

"Around seventy percent."

"It's working far better than we expected."

"Yes. And the enemy is most likely at forty excluding their mana potions. However, if we keep this up, it'll become an unnecessary contest of endurance."

Although a variety of dangerous 5th tier spells flew towards them, Yin knew she was safe and did not have to worry at all. That was because Yang was her vanguard. She could be blindfolded and still put her entire trust in him.

"What about Zenpy?"

"He appears to be more of a support rather than an offensive-type."

The maid magician concentrated fully on attacking, leaving the defense to her partner and the 4th tier protective-based spell「Automatic Prismatic Barrier」.

While their formation was standard, which consisted of a front and backline, it lacked two other main roles — Ranger and Supporter. Thus, the duo had to share the unfilled responsibilities. This was why Duality was particularly famous within the Adventurer's Guild for their unique battle style. Most guilds consisted of at least four to six members, which formed the standard team composition.

"Understood, we will continue and then proceed with 'Formation A3' once we are in range. Will you continue to provide covering fire until then?"

"Not a problem, but I will switch to our standard utility and healing-based spells."

Yang nodded and pushed forward. 

The elegance of his sword continued to dance beautifully in the air, leaving behind silvery traces and afterimages. The sheer precision on deflecting the spells indicated the experience he had. While Yin had seen her partner's swordsmanship countless time, it was always so mesmerizing, like watching a grand performance.

Each time the mage units cast their abilities, the onyx amulet that Yin wore in between her neck glowed faintly.

The fact she had around seventy percent of mana meant that the battle was going well. In fact, extremely well. Prior to the battle, she expected it to be around fifty by this point, if not lower.

Thanks to her necklace, it would refragment the Mana Particles in the air into Mana Essence and then gradually convert the essence into Active Mana. She wore the Legendary-item,「Amulet of Thieving Regeneration」and it was operating beyond her expectations.

Since their enemy was a dozen magicians, the regeneration effect was multiplied by an astounding twelve. And the potency increases based on the opponent's affinity for magic. In other words, this item was absolutely perfect against a group of elite magicians. And because of Unpolite's earlier attacks, an excessive amount of mana essence enveloped the air, which heightened spell potency even more.

This was the main reason why Yin could amplify「Automatic Prismatic Barrier」to continuously withstand multiple 5th tier attacks. She remembered learning this technique from their last God-tier quest, against an endless horde of undead shamans.

Plus, the maid outfit she wore was not to be a cutie patootie. It was enchanted by the Loli Witch of Elite Five named Noa. Under the effects, it allowed the wearer to temporarily exceed their mana cap by threefold for twenty-four hours.

Thus, despite being severely overnumbered, Yin had used the enemy's overwhelming magic aptitude and their spell usage to her key advantage.

In fact, almost everything had been calculated and were within the spectrum of prediction.

One spontaneity was that the only fighter in the Unpolite decided to charge in out of the blue. Yin could only shake her head in total disbelief as one of Duality's greatest obstacles to victory was removed instantly. 

The power of words. 

It was amazing how derision could provoke a veteran warrior into making stupid decisions.

"The Unpolites are changing formation, big brother. The backlines are focusing on healing and mana regenerating. I think they're up to something."

"Let's make use of their mistake then."

Duality changed their speed into a light sprint.

While the item abilities did grant a battle edge, it was more important on how they were used. Anyone could wield them but it takes skills and knowledge for it to reach maximum potential. Until now, Duality had shown only a small portion of their skills, which forced the enemies to take defensive measures. 

However, if these scums were to live, they would certainly gain knowledge about today's battle and reformulate their strategies. This would make future assassination attempts more difficult. Plus, losing would tarnish Duality's reputation as a supreme guild.

Yin knew that failure was not an option.

Although Yang had explicitly stated that the enemy's escape path had been cut off, no such magical traps existed. Yin could tell that her big brother had come in the nick of time after dealing with the soldiers stationed outside.

Luckily, the deception worked in their favor.

But something felt off.

It was almost too easy.

Their opponents were not the average amateurs but a group of renowned veteran mages, feared by many of the best guilds and world organizations. 

What exactly is their trump card...?

Suddenly, a brilliant burst of light emerged from where King Hurley stood. 

The slave girl wailed out in sounds of agony as the burning flames behind her turned darker and darker.

"GAHHHHHHHHHHH!"

Yin's heart sank when she heard the girl continued to scream, begging for mercy and shouting out nonsensical words. 

She had a bad feeling about this.

Yang held out his arms and made a variety of hand signals, She nodded at her big brother's intention and muttered「Greater Enhancement — Magical Appraisal 」. The lens in her spectacles shined in accordance with the 5th tier utility-based spell.

"Enemy skill level?"

"Unknown, but possibly an S-level threat. But her mana level is off the chart, possibly over 9,000."

"A Heavenlight?"

"Not exactly. The original form is still there, however that is something else."

Heavenlight were an ancient race of holy spirits that used to reign the world centuries ago when demi-humans and mythical creatures were more prevalent. Nowadays, most Heavenlights have "ascended" or infused with contracted sentient beings, which allowed the user to cast light-based abilities. 

However, this one was completely different.

Instead of an angelic form with a divine white aura, an atmosphere of pure despair enveloped the battlefield. The halo above her turned completely black and her wings were overflowing in ominous dark energy.

King Hurley laughed manically as the girl gazed at the duo with a pair of soulless eyes.

Yin had not expected this. She did not anticipate the prison girl to be a part of their military strength, let alone the ancient being; Heavenlight.

The siblings halted in their track.

"Dark mana. Blank eyes. Black aura. All potential signs of a spirit contamination. What do you think?"

"It must have been her feelings," Yin said softly. "Those emotions must have built up over the years and exploded..."

Yang looked back and studied his little sister non-verbal expression.

"Change of strategy. Instead of 'Formation A3', we will maneuver between 'Formation A5' and 'B1', focusing on 'Tactic 3, 4 and 61'. I'll be taking care of the Heavenlight."

"'Tactic 3 and 61' requires too much mana if the Unpolites were to attack you. Instead of 'Tactic 4', I'll be using 'Tactic 13' and protecting 'Point Alpha.'"

"Understood, we will begin 'SWITCH' once the timing is right."

"Big brother...?"

"Yes, little sister?"

"How about 'Tactic 143' as the finishing move?"

Yin could tell that Yang wanted to decide against it. It was understandable because deviating from their standard combination would only increase chances of error. In a quest that had worldly consequences if they failed, one might call this risk extremely foolish.

But despite all the rationale, Yin wanted it to happen. 

"Are you sure? We might have to use one of our trump cards."

"Yes." Yin gazed at her partner with a serious expression. She wanted to be true to her feelings. "The girl doesn't deserve to die because of other people's action. She deserves another chance at life."

After a brief silence, Yang nodded and seemed to smile warmly behind his Wolf-Kabuki mask.

"If it's what my little sister want, then I will fully support your decision." 

♦ ♦ ♦

I felt hatred.

Only hatred.

I'm drowning in an ocean of bitterness.

This emptiness in the depth of my soul.

Somehow, I'm being engulfed.

And it's numbing the pain.

Overwhelmed emotion.

Suppressed.

I cannot bear with it any longer.

Somebody help me...

Please...

Kill. Kill. Kill.

If I kill, will these feelings finally go away?

Kill.

Kill first. Think later.

♦ ♦ ♦

The girl muttered a spell and a halberd-shaped weapon emerged forth from motes of dull, black light. Instead of a physical object, the weapon pulsated in pure dark mana.

"Let's do this-!"

Yin nodded at her partner. In a lightning flash, the masked swordsman vanished from his original position and charged forward to the Heavenlight

The maid turned to the Unpolites who seemed to smirk mockingly at her because the frontline had abandoned her. The few who were resting and healing seemed to regain a new sense of energy.

"Looks like she's alone now, how stupid of her brother to leave."

"We can win this after all with the Heavenlight."

"Let's kill her quickly before he regroups."

"All units, capture Yin while the slave distracts Yang." Zenpy waved his hand in a dramatic sweeping motion, "Victory will be ours!"

The maid magician ignored their comments and grabbed four「Scrolls」from her side pouch and threw them up in the air. Instantly, a heatless flame engulfed all of them at the same time, releasing the spell within.

Four elemental golems — Fire, Water, Wind, Earth — immediately materialized above the horizon as the mana essence from the「Scrolls」fused itself, sparking in the air. Within a few seconds, the monsters landed on the ground, shattering the floor on impact.

Yin smiled back to her enemy. The looks on the Unpolite's face instantly changed from a sneer to terror.

"Go forth, annihilate them without mercy. Make sure they do not attack my big brother at all cost."

The golems grunted and hurled themselves forward like flying boulders.

Four「 Scrolls 」for this... Yin silently ached at how much Qian it cost.

As the golems engaged the enemy, Yin swiftly grabbed two elixirs from her pouch and drank them. Her body radiated in shades of green and blue. Immediately, she felt her stamina and mana regenerate at a phenomenal speed. Unfortunately, it did not improve her mental fatigue.

"I can do this," Yin muttered and took several deep breaths, feeling anxiety from the departure of her partner. "I can do this."

While golems were powerful tank monsters, they had low offensive stats and required the summoner to actively take control. To account for their deficits, Yin held her hand forward and chanted 6th tier supporting-based spells.

"「Ardent Censer」,「Knights Vow」,「Locket of Iron Solari」,「Zeke's Herald」"

The water golem formed icicles around its body and armored itself in glaciers while the earth golem summoned tiny rock minions of its own. The fire golem brightens its body, erupting itself like an unstable volcano as the wind golem gained a pair of invisible wings, granting the ability to fly.

Now, this was where the battle becomes harder.

That was because Duality's strength was astronomically reduced when the two siblings were separated. Without Yang's combat synergy, she was simply a Fourth-Attribute Magic user. Her title meant nothing remarkable in a situation against a notorious mercenary group. 

Adding to the mental pressure, 'Tactic 13' and 'Point Alpha' required her to hold her current ground while simultaneously, have her magically appraise the unknown enemy. She needed to gather information and search for weaknesses while her big brother fights the Heavenlight.

This improvisation had resulted from the unexpected turn of event.

Yin felt an overwhelming of stress growing and her mind began to wonder what would happen if they were to lose. She was scared. She could feel her heart beating rapidly. After all, she was still a teenager. Despite the negative thoughts and overpowering emotion, she still smiled.

She smiled because she knew her big brother would never let his little sister down. So she needed to complete her part of the mission and stay alive. That way, they will be able to continue to enjoy the beauty of life together.

As her mind and soul ease into a familiar state of constant flow, Yin opened her eyes slowly, which shimmered in an ocean of mana particles and chanted:

「Supreme Enhancement — Magic Appraisal!」