As William and Kai followed the strange creature, they saw it come to a sudden halt. A few seconds later, the creature leaped down from the boulder it had been standing on.

"What?"

Taken aback, they sped through the gap to see what was happening. As they reached the boulder where the creature had been moments before, they saw it falling into a black portal shimmering with otherworldly energy.

"A Sanctum?" Kai exclaimed upon seeing the portal.

"How is there a Sanctum here? There's no mention of it on the Stronghold map."

William, too, appeared surprised by the black portal's presence. Their shock was understandable— after all, what they saw in front of them was a Sanctum!

Sanctums, or Black Portals, were gateways to isolated spaces of unknown origins. How these portals appeared, what their purpose was and their reasons for appearing were all mysteries to humans, but what was well known was the immense rewards they held.

However, Sanctums were also extremely dangerous, as inside there will be a set of trials to determine whether those who entered were worthy of the rewards. Typically, Sanctums around the Stronghold were marked and controlled by the stronghold's overseers to ensure they were utilized effectively.

A Sanctum would disappear once fully cleared, so humans found ways to repeatedly use them by leaving parts uncleared, allowing the trials, monsters and rewards to regenerate over time. So, what surprised them now was that this Sanctum wasn't monitored by the Mercenary Federation at all.

"Maybe it's a newly formed one," Kai said, gazing at the Sanctum with hopeful eyes.

'This is it!' he thought, realizing this was his chance.

A chance that he desperately wanted to close the gap with his sister.

William understood Kai's intent just by looking at his eyes. Nonetheless, his duty as a guardian took precedence.

"It's dangerous to enter alone, especially since the strange creature jumped in as well." William was suspicious, as it was the first time he had seen a monster enter a Sanctum. He had heard that some intelligent monsters were drawn to the strong Essence leaking from Sanctums - monsters usually stay near the portal instead of entering to absorb the essence leaking out of the portal.

However the strange creature has suddenly jumped into the portal!

The creature alone was dangerous enough, but now there was also the trials within the Sanctum which were unknown.

William wasn't willing to risk his young master's life by carelessly entering the Sanctum driven by his greed for rewards.

Kai understood William's reasons and he was also not foolish enough to overestimate his own capabilities.

"Let's just investigate the Sanctum for now. We can decide what to do later," Kai suggested. William nodded in agreement, and the two of them slowly made their way toward the black portal.

As they approached the portal, Kai concentrated his essence, causing golden runes to appear before him.

[Lunacy of the Black Wings]

[Rank: ----]

Both William and Kai stopped abruptly, shocked beyond measure.

"The rank… it's not visible," Kai mumbled, feeling conflict in his mind. This had never happened before or at least neither Kai nor William had ever encountered such an occurrence.

"This is more valuable than we thought," Kai said.

Typically, Sanctums were ranked from F to S, with further divisions such as F-, F, and F+. This ranking was assigned by Providence based on the Sanctum's danger level.

But this Sanctum didn't even have a rank!

This could mean one of two things, either the Sanctum was too easy to be ranked by Providence, or—

'The Providence can't judge the difficulty of this Sanctum.'

If it were the former, it might be manageable, but if it were the latter, this opportunity was incredibly valuable.

As they considered this and approached the black portal, another message appeared.

[Entry Limit - 1/1]

Once again, they froze.

"Someone has already entered!"

Sanctums generally did not have an entry limit, but some had strict restrictions. The message indicated that someone was already inside.

They didn't consider the strange creature to be part of the entry limit, as Providence didn't count monsters in this regard. This had been verified before when a beast master entered with his beasts—none of his beasts counted against the entry limit, nor did any captured monsters during tests.

So, they concluded that whoever was inside had entered before they arrived.

"Contact the main household," Kai said suddenly his voice filled with urgency. The opportunity was too valuable to let anyone else have it.

"Don't leak the information—keep it as discreet as possible and request support."

Since the Sanctum was under the control of the Mercenary Federation, revealing the matter could lead to conflict. Kai decided to keep it secret and secure the rewards for his own family.

"Ask the patriarch to dispatch the most skilled warriors of our family. We'll encircle the Sanctum."

If the one who had entered failed, they could immediately enter the sanctum and seize the rewards. On the off chance that the person succeeded…

'We will take it by force.'

A cold glint passed over Kai's face as he finalized his plan.

***

The creature possessing Levi leaped into the black portal, and the atmosphere around it shifted abruptly. When it opened its eyes again, it found itself enveloped in a dim twilight, with the sky above being a swirling mix of dark clouds and mists. The ground beneath its feet was uneven and rough, scattered with jagged rocks and deep cracks.

The creature glanced ahead, its monstrous eyes gleaming with intelligence.

Twisted trees, with branches resembling skeletal fingers, cast long, eerie shadows. Green luminescent fungi clung to the tree barks, casting a ghostly glow over the surroundings. And a heavy fog hung in the air, obscuring vision and adding to the chilling atmosphere.

As the creature surveyed its new environment, a vicious smile spread across its face, as if it recognized the place.

Then, suddenly, a sharp pain pierced its mind, causing it to clutch its head in agony.

"Seems our little sunshine is trying to wake up," it said, its smile widening.

"Fine, enjoy the small gift I have prepared for you."

The creature growled with ferocity one last time before collapsing to the ground.

---***---