Four days later, Fifth Floor.
Lillian, Kizmel, and Yui stood before the BOSS room, staring at the countless Sudoku-like puzzles covering the door. Lillian rubbed his temples.
Their efficiency in the past few days had been staggering—an average of one BOSS every two days. Even players watching the increasing number of portal options were shocked. Their levels were still low, yet they could reach the fifth floor. No one dared follow, as even small monsters in the wild were higher level than them.
This fascinated them and infuriated major guilds—they hadn't even had a chance to explore the new floors before it was conquered. If this continued, guilds might never even find the BOSS; sometimes, the BOSS room was cleared before anyone located the BOSS.
Meanwhile, the trio ignored others entirely, now standing before the fifth floor BOSS door.
The massive door was covered in hundreds of Sudoku puzzles, some interlinked. Anyone who disliked math would get a headache—including Lillian. Math had never been his strong suit; his favorite subjects were language and history.
"This floor's theme is 'puzzles,'" Lillian said.
"These Sudoku problems must be crucial to defeating the BOSS. We need to solve them."
He started calculating the first puzzle reluctantly. With more players, it might have been easier to share the workload. But alone, it was tough. Lillian prepared for at least a day of work—until Yui suddenly recited a sequence of numbers:
"8,3,4,1,5,9,6,7,3."
Lillian froze, quickly noted them down, and asked in surprise, "Yui, you solved it just by glancing?"
"Yes," Yui nodded, looking at him curiously.
"Is that wrong, Lillian-nii? I felt the numbers jump into my head."
"Completely correct," Kizmel confirmed.
She solved it too?
Lillian realized the NPCs' computational skills were incredible… or perhaps, as NPCs are based on numeric logic, they were naturally more sensitive to numbers.
Shaking his head, Lillian decided not to overthink it. If anything, it made the Sudoku easier.
"Let's enter the room."
Pushing open the door, Lillian felt more confident tackling BOSSes than before. With Kizmel's help, he was far more relaxed—their growth pace was almost in sync with the BOSSes on each layer, terrifyingly so.
The BOSS room was wide, somewhat like the first layer, but the objects inside were different—this time, a mechanical type, not biological.
Floating in the center was a cube, resembling a Rubik's cube, fitting the layer's puzzle theme. But unlike a normal Rubik's cube, each face was golden with numbers 1–9. Lillian suspected it connected to the number sequence Yui had just solved.
Zzz… zzzz…
As they stepped in, the cube emitted electric crackling sounds, then rotated violently. It rapidly expanded to nearly two meters per edge, and its name and HP appeared above it:
[Irrational Cube]
No words were needed. Lillian and Kizmel exchanged a glance and attacked from different sides. After so many battles, they had developed perfect coordination. The cube's reaction was sluggish—it took damage before it could even respond.
Lillian's greatsword struck the target, producing a crisp metallic clang. He looked up, surprised to see the BOSS's HP hadn't decreased at all. No guard break? Impossible. Even though his greatsword had seen better days, it had already been reinforced to +7, with a sharpness of 170—more than enough.
He glanced at Kizmel. Her attack also hit the BOSS, yet its HP remained unchanged. Something was definitely off.
Zzz—
The sluggish Cube suddenly counterattacked. Light appeared at each of its vertices, and gray lines traced toward Lillian. Acting like pre-aim indicators, Lillian instinctively dodged. A second later, multiple white lasers shot into the spot he'd just occupied.
Too dangerous… Why isn't it taking damage?
As he dodged, he carefully observed the numbers on the BOSS's surfaces. He suddenly realized that after each attack, two sides seemed to shift… no, the metal plates rotated whenever hit.
"I get it!" He exclaimed. Turning to Kizmel, he instructed: "It's invincible in its current state. We have to hit its metal faces in the order '834159673' solved by Yui. Don't strike yet—I'll handle it!"
Once he found the method, the task became easier. Every successful hit caused a metal face to rotate. After a few hits, Lillian discerned the pattern: "first top, then right." Mastering the sequence, he began striking the panels in order, while Kizmel kept the BOSS distracted. Within three minutes, the final panel aligned with Yui's number sequence. The metallic numbers shattered with a series of "bangs," falling to the ground and revealing a smaller, black cube inside.
"This must be the 'true body.'"
As expected, this level was puzzle-focused; even the BOSS required solving a puzzle to be harmed. Now that the true body appeared, Lillian swung his sword, and the invincible state disappeared—HP began to drop.
Enraged, the black cube extended four long arms composed of dozens of small cubes, swinging at the two of them. It looked somewhat like Apocalymon from the original Digimon, though certainly less formidable.
With the puzzle portion complete, the remaining fight was pure combat. Lillian and Kizmel's synergy and skills quickly ended the battle within five minutes, shattering the Irrational Cube into fragments.
Clap.
The two exchanged a practiced high-five, then did the same with Yui, who had come running in with her small shield.
Exiting through the gate and down the stairs, they finally reached the sixth floor—a critical level where the major quest would provide new clues. Before continuing, Lillian received a message from Argo.
{The Laughing Coffin guild appeared on the 4th floor and is attacking other guilds.}
Three days ago, this guild officially appeared. Lillian had instructed Argo to be cautious and track them, noting that this guild represented a true red-name PK threat. Argo, aware of their early formation, immediately gathered intelligence—Laughing Coffin was still unorganized, far from the skilled, elusive guild seen in the original storyline.
{Got it. I'll head there immediately,} Lillian replied.
He was used to eliminating threats at their root. Though he could ignore them—the Laughing Coffin guild posed no direct threat to him—he wasn't entirely self-centered. If he had the means, he didn't mind helping others. Most people acted this way: help if possible, otherwise self-preserve. Lillian, however, couldn't ignore a significant threat, especially one tied to past grudges, potentially set up by PoH. If so, he intended to settle the score immediately.