The area boss that players had to face this time was a grotesque remnant from an ancient era… Biceps Archelon, a colossal two-headed turtle.
Its name already gave away part of its appearance: a gigantic turtle with a body stretching over twenty meters long, a dark, steel-like glossy shell covering nearly its entire form.
Its flanks were guarded by layers of hardened carapace, like moving fortress walls, causing most player attacks to slide off harmlessly.
Only its soft underbelly and two massive heads revealed any weakness.
Scout parties had encountered it before.
Though they paid a heavy price, they brought back invaluable information.
The monster possessed at least three massive health bars, and even after being pressured for more than an hour, its HP had only been pushed down through the first bar.
That meant the real fight had only just begun.
According to reports, Biceps Archelon had three primary attack patterns. The first was a simultaneous bite from both heads, its speed terrifyingly fast, its damage immense, enough to crush any fully geared player caught in range.
The second was a water slam from its enormous flippers, creating towering waves that swept across the battlefield, throwing anyone nearby off their footing.
And most dangerous of all were its charges. Players could see the telltale sign: both heads turning toward a single direction, then lifting high into the air.
Moments later, its massive, stone-like body would surge forward, demolishing everything in its path.
The length of the battle wasn't simply due to weak players, the very terrain worked against them.
The battlefield was a vast lake inside a volcanic crater, a domain the monster claimed as its own.
Whenever it dove beneath the waters, the expansive surface swallowed all trace of it, leaving raiding groups disoriented and lost.
That lake blocked the only road to Yofel Castle, the Dark Elf stronghold and gateway to the rest of the fourth floor.
Of course, some might argue that "the only road" wasn't absolute.
Players could risk climbing the sheer cliffs and skirting the crater's rim.
But anyone who had tried knew it was nothing short of suicide, far more difficult than facing the beast itself.
"Move! Move! It's about to ram the left line of boats!" urgent shouts echoed.
The once calm surface of the lake erupted violently as Biceps Archelon's hulking mass surged beneath the water.
One quick-witted player leapt to the prow, raised a bronze gong, and struck it with all his might. The resounding note thundered out, rolling across the lake like a tolling bell of warning.
Immediately, dozens of gondolas packed with players pivoted, rowing furiously to escape the danger zone.
Even so, the rocking decks sent many stumbling; some even tumbled into the water, their cries mingling with the roar of crashing waves.
"What a damn inconvenient battle…" Ren muttered under his breath, lips pressed tight before exhaling a sigh.
He leapt from one boat to another, his boots landing on soaked planks that shook violently beneath the surging waves.
Every jump was a trial of balance, one misstep meant plunging into the dark waters below.
He hadn't brought his own small gondola here; it would never withstand the storm. Instead, Ren stuck with Agil and his party.
According to the plan, the main force, including the Aincrad Liberation Squad and the Dragon Knights Brigade, would take the vanguard, engaging the boss head-on.
Meanwhile, smaller groups, such as Kirito's party and Agil's, were tasked with striking at the flanks, diverting attention.
Lind, commander of the Brigade, had repeatedly assured everyone that while the boss's bites and flipper strikes were dangerous, they weren't instantly fatal."If need be, let the boats take the hit, it's fine," he had declared, as if trying to pour courage into every player.
Still, none dared underestimate the monster's charges.
For that reason, the flagship Leviathan, the largest gondola owned by the Dragon Knights Brigade, had been equipped with a gong system for signaling.
Each strike of the gong carried one absolute order: evade immediately, at all costs.
The sound of the gong boomed again, reverberating through Ren's chest, his heartbeat falling into rhythm with its heavy tolls.
All the gondolas tilted in unison, tossed about violently like leaves swept into a storm.
The surface frothed and sprayed as the colossal beast rose. Its moss-covered shell scraped along the water, leaving a great swell in its wake, cold waves slamming against boat hulls.
"Left flank, attack! Keep your distance, don't get cornered!" Lind's voice thundered from atop the Leviathan, clear and commanding, cutting through the roar of the waves.
Instantly, countless skills were unleashed.
Streaks of multicolored light arced across the water, like blazing arrows piercing toward the turtle's darkened bulk.
The impacts resounded, but left only shallow cracks on its stone-like hide.
Ren narrowed his eyes, gaze locked on the monster. He could feel each tremor of its collisions shaking through the boat, rattling his entire body.
Beside him, a smaller gondola surged forward along the edge, rocking violently with the waves. Ren cast it a brief glance, onboard, a group of players braced themselves to unleash their next strike.
Kirito had leapt all the way to the edge of the boat, his black hair swept back by the wind. He darted forward, his steel blade spiraling as it unleashed a seamless chain of strikes.
Right behind him, Asuna tilted her head slightly, giving orders in a voice clear and sharp as a blade, "Cover Kirito's retreat! Don't let it knock the boat over!"
At her command, the small party moved instantly, coordinating as if they had trained for this moment. The gondola tilted, creating space for Kirito to spring back just as a violent wave came crashing in.
Ren stood on the edge of Agil's boat, his eyes narrowing.
"Ren, hold on tight! It's turning this way!" Agil's voice roared, snapping him out of his thoughts.
Ren drew a deep breath, his hand tightening around his sword hilt. The water still howled across the battlefield, white spray crashing up as though to swallow every vessel whole.
After a brief pause to recover lost HP, Ren stepped forward to replace the front line without hesitation.
He stood tall at the prow of the rocking gondola, his gaze locked firmly onto the target.
The massive turtle had just lashed out with both heads at the left formation, leaving an opening on its right flank.
Now's the time, Ren told himself, and launched forward.
Together with several other core players, he led the spearhead assault, weaving past the fortified shell to strike directly at the gaps, where the beast's rough hide was exposed.
His blade traced a radiant arc, combining with his allies' skills, each strike landing hard against the turtle's thick neck.
Its roar of pain thundered like a storm, and the towering HP bar above it sank in heavy chunks.
The enraged beast swung its tail like a stone pillar, sending waves surging that tossed entire sections of boats aside, water bursting skyward like walls cutting across the battlefield.
Ren lowered his stance, bracing himself on the soaked deck, eyes never leaving the monster, ready for the next strike.
The giant turtle continued to bellow, its two heads snapping at any gondola within reach. Its hulking body surged again, the surface shattering into waves that threatened to engulf everything.
But this time, Ren and the right flank avoided being caught in the chaos. Thanks to the two main forces holding the boss's attention at the center, its violent charges were diverted at just the right moments.
In the distance, Kirito and Asuna led their group in from the left flank, unleashing a chain of sword skills that synced perfectly with Ren's strikes from the right. Their sword lights crossed, blazing across the entire lake.
The monster's massive HP bar plunged down another huge chunk, leaving only a third remaining.
Ren panted lightly, but his hand stayed firm on the hilt, his gaze unwavering. "Almost… just one more round."
Yet moments later, Ren noticed something wrong. The turtle's heavy bites no longer came as fast and relentless as before.
Its flipper slams no longer stirred waves strong enough to capsize boats. Instead… they were slower, weaker, as if the monster were deliberately holding back.
A chilling draft ran down Ren's spine. He frowned, eyes fixed on the creature's movements. "No… it's not running out of strength."
Flashes of memory from dozens of battles surged through his mind. The oldest pattern, yet one that never failed, bosses always saved their deadliest skill for the final phase, when their HP was on the brink.
"Don't tell me…" Ren muttered, his heartbeat pounding. The scouts before had surely never pushed the monster this far.
If they had reached this last threshold, they would have called reinforcements long ago to finish it.
His grip tightened on the sword as he shouted, his voice thundering louder than the waves crashing against the hull, "It's about to unleash a special attack! Everyone, steer the boats back, far back, as far as you can!"
The urgent cry made several smaller groups falter. Some players turned to look at Ren, stunned by the unusual certainty blazing in his voice.