Chapter 124 – Battle in the Underwater Cave

As we explored the submerged passages of the Magic Light Water Vein, I gradually realized we were being led deeper and deeper.

In a normal exploration… there would be some risk, but we’d swim a bit through the submerged sections to check what lay beyond the passages. However, with this being primarily underwater, the normal passages gradually decreased until we were spending more time completely submerged than not.

The deeper we went, the dimmer the glowing crystals growing from the rock surfaces became. As if to compensate, monsters like luminous jellyfish and anglerfish that didn’t actively attack us occasionally patrolled the area, illuminating the cave with their pale blue light. It truly had… the atmosphere of a deep-sea cave.

Since using magical light attracted monsters, we were all currently using Night Vision Magic.

From beyond the narrow cave that continued in a detouring path, a bright light. Having advanced through dark waterways, one would naturally want to rush toward it joyfully.

First, I canceled the Night Vision Magic to let my eyes adjust to the light level. I reapplied the Bubble Shield, set up mental defenses with the Psycho Field—preparing everything needed to charge into the large chamber.

While we prepared to enter, Sheila and Seraphina gathered sounds from a position where they wouldn’t be detected and analyzed the noises from the large room.

“One large type and one humanoid type. Not too many detectable by sound, but it’s a fairly large room… I think. There’s considerable space above and below too.”

Detectable by sound, huh. In the Magic Light Water Vein, there are those that don’t move until we get close.

Like the Arrow Urchin that shoots needles, or the Cloaking Kelp that entangles and attacks. In a large room where a big one seems to be waiting, those kinds are naturally present too.

“What should we do?”

“If we want to proceed further, this seems to be the only passage…”

We hadn’t found any stone tablets on this floor. If we retreat, we’d need to use the Red Transfer Stone, and giving up on exploring this room would mean being stuck here until the labyrinth’s structure changed.

“Once we enter the room, use the Defense Field immediately. There’s probably Kelp, so let’s fight using Aerial Combat Gear to avoid going near the bottom. First… to avoid being pincered, let’s properly block the passage behind us.”

Following Ashley’s instructions, Lavigne sealed the passage we came through with ice.

“Marlene and Seraphina are Rearguard. In an emergency, use the Red Transfer Stone in the passage to secure everyone’s retreat route, so keep a close eye on the battle situation. Ashley, Irmhild, and Lavigne are Midguard. Use String Resonance and ice to interfere and prevent them from reaching the Rearguard.”

I relayed the detailed strategy to everyone. Grace and I are Vanguard. Sheila will act flexibly, either joining the Vanguard or providing support as the situation demands.

“Alright. Let’s go.”

The moment we charged into the large room, I deployed the Defense Field to cover the entrance. First, I focused on assessing the situation.

Above the room, a swarm of glowing jellyfish. They seemed to be illuminating the interior.

Brightness Jellyfish. Those jellyfish are harmless unless you approach and touch their tentacles—but if they get caught in magic, the room will be plunged into darkness.

Below was a forest of Cloaking Kelp. From between those kelp, urchin needles shot out and were blocked by the Defense Field.

This much was within our prior expectations.

In the center of the room. Two large monster shadows there.

Swimming toward us majestically was a long-necked turtle the size of an elephant. Its skin was rugged like rock surface. With its ferocious face, it looked more like a serpent than a turtle.

Shield Archelon. A powerful monster with a sturdy shell whose edges are sharp like blades. It attacks by spinning.

The other was a Dead Shark. A shark with bones exposed in various places, clad in shimmering black-purple magical power—a zombie shark, just as it looked, an undead-type monster.

And—standing with arms crossed as if commanding those two, another glared down at us.

“A Guardian!”

Captain Nautilus. A rather peculiar-looking monster with a nautilus head, wearing a pirate captain’s hat and coat.

“I’ll take that one. Grace, you handle the turtle. Irmhild and Sheila, the shark.”

We split up to deal with them accordingly. The enemy formation was quite powerful.

Grace engaged the turtle. She met its high-speed spinning slash attack with her axe. The turtle’s massive body and Grace’s slender form clashed head-on—showing us a rather surreal scene where both were repelled. Archelon should be handled by Grace.

Against the Dead Shark—when Irmhild resonated her String Resonance, it clearly disliked it and tried to distance itself. That’s when Sheila launched her attack. Slash attacks aren’t exactly effective against bone, but a strike imbued with Fighting Spirit works well on undead.

The urchin needles were being blocked, and we maintained distance from the kelp.

Merfolk also emerged from the kelp forest—but Ashley and Lavigne handled them.

Their spears and half their bodies frozen, Ashley easily smashed their heads. Though they were outnumbered, Ashley’s movements even seemed relaxed. Her close combat skills had improved considerably through daily training with the Aqua Golem. She deflected the Merfolk’s spears with the Sword Boar’s shield, then struck their exposed torsos hard. When the Merfolk recoiled, Lavigne finished them off by impaling them with ice spears.

Those who avoided that were stalled by the Defense Field and sliced to pieces by Dullahan, who held position near the entrance, then sank. Marlene’s own Lightning Strikes didn’t even get a chance.

At this rate—there’s no way they’ll break through to the Rearguard. Caduceus is Mid-Rearguard support. It’s best to have him cover our allies.

I charged toward Nautilus. Whether pleased that I, a magician, was closing the distance, it wriggled the area around its mouth—whether beard or tentacles was unclear—and shook its shoulders.

Seems it’s laughing. It drew two cutlasses from its waist to meet me. The cutlasses had a strange texture with a pearlescent sheen.

Apparently, Nautilus—can operate on land too. It charged into my Bubble Shield without hesitation, and we crossed blades with Ouroboros and the cutlasses.

I tried to entangle the cutlass with Ouroboros. But Nautilus seemed to sense my intent and skillfully evaded, then thrust with its free cutlass. I deployed a shield. While blocking the thrust, I kicked off the shield to leap backward, then faced it again.

As expected of a Guardian. It seems quite skilled in close combat. We both stepped forward simultaneously.

An exchange of strikes and slashes. Nautilus wrapped its cutlasses in Lightning Strike and launched them with its slashes. I responded by wrapping Ouroboros in purple lightning. This was to use Lightning Magic to control and prevent the opponent’s electricity from reaching me.

Occasionally, urchin needles flew from unexpected directions. I blocked them with my shield or dodged while striking Nautilus.

No problem. The multi-directional attacks from Luceriage’s time were much denser than this.

While the clashing of blades echoed, I also paid attention to my comrades’ battle situations.

The Dead Shark opened its large mouth and lunged at Sheila, but she easily evaded. She generated a shield to deflect the attack and cut off its fin with a slash.

But being undead, it showed no sign of writhing in pain. The severed fin was still

alive

(

…

)

. It flew toward Sheila like a shuriken. She slashed it back two, three times with her dagger wrapped in Fighting Spirit, scattering the black-purple aura until it became an inert corpse—sinking to the bottom of the large room.

Meanwhile, the Dead Shark itself circled around from behind trying to bite Sheila, who was dealing with the fragments, but when Irmhild resonated her String Resonance, the aura surrounding the Dead Shark destabilized, causing it to falter momentarily.

Sheila calmly moved away from the spot, and the large jaws passed through where she had just been.

“I’ll help!”

I thought it would become a battle of attrition until we wore it down, but Seraphina approached Irmhild’s shoulder.

“Then, I’ll leave it to you.”

When Irmhild resonated her String Resonance, the sound waves that should have spread radially gathered in Seraphina’s hands and transformed into magical light.

Similar to the Resonance Bullet she used against me when she was rampaging. Sheila glanced at it sideways, then dodged the Dead Shark’s attack widely. She exchanged looks with Irmhild, and both smiled.

The Dead Shark flipped around and launched another attack.

Sheila crossed her daggers and slammed them into the shark’s snout, stopping it head-on. An unusual defensive move for Sheila. Unable to completely kill its momentum, she was pushed backward.

But—that was exactly Sheila’s plan.

She had maneuvered so that the Dead Shark, herself, Irmhild, and Seraphina were aligned in a straight line.

“Here I go!”

As Sheila and the Dead Shark closed the distance, Seraphina fired a Light Bullet. As if signaled by her voice, Sheila crouched—then kicked the Dead Shark’s head with both feet wrapped in her shield and flew away.

From behind the departing Sheila, a Resonance Bullet of concentrated String Resonance flew in, hitting the Dead Shark’s snout directly, and the sound waves propagated through its entire body.

I’m not sure what sensation that gives an undead—but against the Dead Shark writhing and contorting, Irmhild’s tail launched a spear-like arrow. An arrow like a spear wrapped in Fighting Spirit. Literally using her entire body’s spring-like power, the strike was overwhelmingly powerful. It entered through the mouth and the tip emerged from its back. Ruthlessly piercing through.

—Then. Sheila descended from directly above. The brilliance of Fighting Spirit erupting from her reverse-gripped dagger. Trailing a luminous tail like a meteor.

At the last moment, she canceled Levitation. Returning the weight to her body, she drove her dagger deep into the Dead Shark’s cervical spine, then kicked off her shield in midair to gain more momentum, and as she passed by, she severed the Dead Shark’s head.

Even then, the Dead Shark still moved. As if expecting this from previous battles, Irmhild fired arrows like a rapid-fire cannon. Seraphina concentrated the String Resonance sound into the arrowheads. The aura surrounding the Dead Shark visibly diminished.

Grace versus Archelon was a match of power versus power. Normally, you’d lure it onto land to somehow finish it off. That she can confront it head-on underwater—though probably thanks to her equipment—is characteristic of Grace.

As if to wear down its spinning momentum.

She struck with her axe from the opposite direction. When the Spark Light scattered and its spin momentarily slowed—from below, Grace struck upward with a knee strike. Hit hard in the vulnerable underside, Archelon let out a groan of agony. Yet, due to its massive size and toughness, it launched another spinning attack.

Mid-spin, it extended its flippers from its shell, altering its trajectory to avoid matching the axe.

Dodging two, three times, Grace, having read its movements, flew directly into the path of the spinning attack. She met it head-on with her axe, killing its momentum. It seemed like the same scenario would repeat—but its head emerged from the shell and it attacked Grace with its large jaws.

Grace met that with a punch imbued with Fighting Spirit. She wasn’t holding her axe. A chain wrapped in Fighting Spirit entangled Archelon’s shell from below.

Struck and bewildered, Archelon tried to distance itself from Grace, but Grace didn’t resist and allowed herself to be pulled along, sticking to Archelon.

Then, she took position on its shell. Pulling the chain to firmly secure herself, she paid no mind to Archelon spinning to throw her off, and began striking the shell with her axe wrapped in Fighting Spirit. A tremendous sound echoed.

Under the repeated axe blows, even the shell shattered and blood gushed from its back. Grace—seems intent on breaking through head-on from start to finish. Apparently, she has the goal today of returning to her original movements to gauge her own growth.

—Now. The battle situation favors us. Once the big ones are dealt with, they’ll move on to cleaning up the small fry—so I should feel at ease and focus on my own fight.

The battle with Nautilus—is close combat with rapidly switching offense and defense.

If I use Great Magic and take out the jellyfish, destroying the light source would worsen my comrades’ visibility. And with a light source present, we can’t rely on Night Vision Magic.

So I launched a magical light beforehand, but Nautilus scattered it with Lightning Strike, as if to thwart me. Worthy of a Guardian. It seems to grasp the situation well. It’s been positioning itself with the jellyfish behind it, maneuvering to prevent me from using large techniques. Quite a clever move.

In that case, it becomes about how—I slip past the opponent’s swordsmanship and land attacks. Fine by me. A technical fight is exactly what I want. This is getting rather enjoyable, isn’t it?

Since I’m wrapped in a Bubble Shield, even if I separate my Mirage Body to feint, it gets noticed immediately.

I deflect the two lightning-wrapped cutlasses with Ouroboros and evade with my shield. I meet the water bullets piercing through the Bubble Shield with ice bullets. Lightning Strike, water bullets, dual wield—quite versatile.

I slam Ouroboros against the crossed cutlasses.

Repelled, distance opens between us, and Nautilus spreads both arms. The area around its brow electrifies—Lightning Strike, incoming.

Without hesitation, I deploy my shield directly in front and charge through. If it can be blocked, breaking through the Lightning Strike itself isn’t difficult.

Probably not expecting me to charge straight through the attack, I fly into Nautilus’s chest.

From below—I show a stance as if scooping and striking upward with Ouroboros, which lets out a mocking growl. Ignoring Nautilus hastily bracing itself, I fly upward.

I anchor myself above using my shield deployed overhead. I strike down at Nautilus, who’s staring up at me dumbfounded, with the reverse end of my staff.

It explodes against its shoulder. A hard impact and the sound of something shattering beneath the captain’s coat. So it’s clad in nautilus shell like armor. Then, that probably isn’t a fatal blow yet.

But. The situation has me above, Nautilus below. Below is only the spreading kelp forest.

“Checkmate.”

I deploy a huge Magic Circle at the tip of Ouroboros. Nautilus’s pinhole-like eyes seemed to widen enormously.

A moment later—a massive Lightning Strike engulfed Nautilus.