The first thing to come into view was an enormous humpback whale, some thirty or forty meters long: the merfolk king's transformed body. Unlike the other royals, his mana had grown stronger after transforming. In his present state, even Maysa might struggle to guarantee victory against him one-on-one.

Under ordinary circumstances, Turan would have marveled at the enormous whale's appearance and power. Not now. The presence of the monster approaching behind it dwarfed even his.

'The great sea serpent...'

When he had acquired the Mimic Holy Relic, Turan had marveled at the grandeur of the great sea serpent's corpse, lying dead alongside a man he presumed to be one of the Freyans.

But the sight of the serpent moving now made that memory seem paltry. Admiring the majesty of a lake or mountain was one thing; seeing that landscape come to life and move was something else entirely.

Its appearance, too, had changed considerably since then. Rather than the moss that had once coated it, brilliantly gleaming silver scales covered its body. Here and there, damaged sections were filled with something resembling swirling wind, much as wraiths filled their missing parts with green radiance.

Then there was the vast reserve of mana within it, revealed by the Holy Relic's senses. It was comparable to the Head of Ravista he had met before. That would likely be their prize from this hunt.

"What a sight..."

Turning his head, Turan saw Solif murmuring with a broad grin. Given his longstanding obsession with ancient myths and legends, the realization that he was facing a truly mythical monster seemed to fill him with renewed delight.

"Let's go!"

With that shout, Turan rose into the air alongside Maysa and headed toward the great sea serpent. Solif followed a moment later, clutching Vije's legs, while the merfolk royals approached through the sea.

For a moment, Turan shuddered at how much larger their target grew as they approached. Then he stopped and formed a wind channel. The violent eddies whipping about in every direction made it harder than usual, but he managed.

With that done, he drew his secret weapon from his pouch. It was a sling much like the one he had used before, but on a very different scale, both in the length of its cords and the size of its stone pouch.

Where his old sling had been just large enough to throw egg-sized stones, this one could hold a boulder almost as large as a human torso, allowing for a little exaggeration. Turan loaded it with a large rock he had prepared in advance and began swinging.

'Still feels awkward...'

He had more than enough muscle, but throwing stones on an entirely different scale from what he had used all his life could hardly feel normal. He had practiced for the past few days, but how could that compare to a lifetime's experience?

Reinforced with mana, the sling spun smoothly without snapping under the huge rock, building centrifugal force. Moments later, the boulder shot down the wind channel at several times the speed of sound and struck somewhere on the great sea serpent's head.

[□-----■-----□-----!]

The monster, which had been cleaving through the sea toward the island without hesitation, writhed and screamed. To a creature that size, the rock was no larger than a fingernail-sized pebble striking an ordinary person, but the immense mana within it delivered force far beyond its size.

Naturally, its scream was far more than an animal's cry. The scream—or roar—that erupted from its gaping mouth sent ripples and tidal waves surging through the surroundings.

Ordinary people hearing it from anywhere nearby would likely have died from the shock alone. Even Turan had to grimace and clamp both hands over his ears.

"Ngh..."

After screaming, the great sea serpent turned its eerily glowing yellow-green eyes toward Turan and immediately retaliated. Waterspouts formed on the sea, and several swaying columns of water rose and hurtled toward him.

He quickly flew aside to avoid one or two, but well over a dozen columns were coming at him. Flight magic was not a particularly robust technique by its very structure. One bad hit would bring him straight down.

At that critical moment, Turan detonated a prepared handful of Spirit of Fire beside his body. An impact like a blow to his flank sent him hurtling clear of the water columns' reach.

"Whew..."

One column that passed him struck the island's shore behind him with astonishing results. It gouged a trench dozens of meters long and several meters deep into the beach. A direct hit might not kill him outright, but it would certainly do serious damage.

While Turan held the serpent's attention, attacks began coming from other directions.

"Aaaah!"

With the heavy storm clouds allowing her to unleash lightning almost without spending mana, Maysa scorched the serpent all over in a furious barrage. Hanging from Vije, Solif darted around its body, burning and scraping away scales with golden whips.

Below, the merfolk royals, transformed into all manner of sea creatures, harried the serpent and wore away at its body with their specialties. The most conspicuous among them was, naturally, the merfolk king in his enormous whale form.

The whale rammed its head into the serpent's flank with a tremendous boom, as though two mountains had collided.

"Ha..."

Turan could not help marveling that sheer size could produce such force, even though the king's mana was nowhere near dozens of times greater than that of Rowina, whom he had fought recently.

Then again, though the whale was less than half as long, its body was far thicker. Their total weight could hardly be all that different.

Perhaps deciding that its tormentors in the sea were easier to catch than those flying overhead, the serpent roared and coiled its long body around the whale. A jellyfish drove its tentacles into the scales and released electricity to break its grip, only to be crushed by a lash of its tail.

'That one's dead.'

The first casualty visibly unnerved the merfolk royals. As the serpent opened its jaws to bite into the whale's flank, Turan flew closer, showered its face with Spirit of Fire, and immediately ignited it.

Contrary to his expectations, no grand explosion followed. The black powder had been soaked in the storm. He could protect it from getting wet close to his own body, but doing so while sending it far away was difficult.

"Damn..."

He had known contact with water greatly diminished the Spirit of Fire's explosive power, but to think it would not explode at all!

His surprise at the unexpected development lasted only a moment. Dismissing the failed approach, Turan hurled a stone at the enormous eye, held steady as the serpent bit into the whale's flank. In his haste, he used one of his usual small stones rather than another of the large ones.

The attack was less than a speck to the enormous creature, but like anyone poked in the eye, the serpent writhed all over and hammered the sea with its tail. Dozens—no, hundreds—of water columns like the ones that had attacked Turan rose and thrashed wildly across hundreds of meters in every direction.

"Watch out!"

Turan hastily carried his voice with wind magic, but Solif and Vije, who had been flying around attacking its body, had not yet escaped its range. Through the raging storm, he glimpsed the man and bird faltering. Then a column of water engulfed them and dragged them beneath the sea.

'Damn...'

Fortunately, the Mimic Holy Relic's senses allowed Turan to see even through the storm. Flying straight over, he saw Solif manipulating the water to emerge from the sea.

"Are you all right?"

"I am! But I think Vije's wing is broken!"

Turan lifted both of them and carried them back to the island's shore. Looking at the whimpering Vije, Solif spoke in a voice full of self-reproach.

"Damn it. She could easily have dodged that if I hadn't been there."

Bodies that were fragile relative to their mana were a chronic weakness of flying monsters. As an upper-tier monster, Vije could certainly withstand attacks from most enemies, but the creature before them was literally a monster out of myth.

Even this outcome was thanks to the defensive magic tool Turan had hung around her neck, one he had taken from the Baraha remnants. Without it, she might have been hurt far worse, or killed. He carefully set her broken wing and fed her a restorative potion.

"Feeling any better, Vije?"

Vije nodded as though she were fine, but Turan could indirectly feel her pain through their soul bond. Flight was a delicate art, and with a storm raging madly around them, she would have difficulty rejoining the fight right away.

Turan told her to shelter farther inland, then placed Solif on the back of the nearby sea turtle merfolk. Getting close would be difficult, but providing covering fire from there should still help.

Returning to the desperate struggle against the serpent, Turan frowned at the changed situation. Little time had passed, yet two more merfolk royals were dead, and the enormous whale was bleeding from wounds all over its body.

["Are those two all right?!"]

Maysa sent her voice through wind magic without pausing her attacks on the serpent. She must have seen Vije and Solif get shot down.

Turan signaled that they were fine, then took out another large boulder, formed a wind channel, and hurled it. The serpent staggered under the booming impact.

'It does seem to be taking a fair bit of damage...'

The problem was that the merfolk royals had begun to grow noticeably passive.

Perhaps because they fought in the sea rather than flying overhead like Turan's party, the serpent prioritized attacking them, within easy reach of its jaws. Having suffered considerable losses, the royals were now edging back instead of actively engaging it.

They were probably thinking much as Turan did. If they sacrificed too much here and upset the balance of power, his party might try to purge them after the battle.

With three already dead, they clearly would not accept further sacrifices unless Turan's side took risks or suffered casualties too.

'No other choice.'

Turan drew its attention by flying around its head, whirling a boulder in his oversized sling. The serpent raised vortices as before to swat down the threatening gnat, but each time, Turan used the Spirit of Fire to blast himself out of the way.

After doing this over and over, his entire body ached as though he had been beaten.

'This is killing me...'

Still, stepping forward had paid off. Seeing his efforts, the hesitant merfolk royals began attacking aggressively again. Far away, Solif was also drawing the serpent's attention, firing arrows and spears of light.

As for Maysa, for some reason she seemed to have switched from lightning to physical attacks made of light, like Solif's. Perhaps she had decided lightning was less effective against the serpent than she had expected.

The fierce exchange continued for tens of minutes. Realizing his mana had dwindled considerably, Turan withdrew a little to catch his breath. Maysa moved forward to take over drawing the serpent's attention.

'I'm starting to wear out... When is it going to fall?'

According to the Holy Relic's senses, the great sea serpent's mana had fallen to less than half its original level. Parts of its body had been destroyed and replaced with swirling storm, as was typical of wraiths.

Wraiths were far more structurally resilient than living creatures, but they were not immortal. It had to be feeling the damage.

The problem was that Turan's party and the merfolk royals had lost just as much strength and were equally exhausted. Three of the nine royals who had originally joined the fight were dead. On Turan's side, Vije's incapacitation made it difficult for Solif to engage actively.

With the balance so precarious, a single mistake could turn the tide against them.

'Should we give up?'

He considered the sudden thought for only a moment before shaking his head and dismissing it. Giving up after coming this far would be such a waste. It felt as though they needed only a little more effort.

'If only it weren't for this storm, things would be easier.'

If he could send large quantities of Spirit of Fire from a distance and detonate them, the fight would have been much easier. Attacking through a sling was a reasonably efficient way to conserve mana, but it still fell short of explosive attacks using the Spirit of Fire.

If he could stop the wind and rain, or place Spirit of Fire directly inside the serpent's body—or on its surface, shielded from the storm—and detonate it, he might inflict considerable damage. With one side blocked, the explosive force in the opposite direction would be maximized, too...

A moment later, his eyes widened as an idea flashed through his mind.

'The sling's pouch shields it from rain. Detonating it would produce a strong kick.'

At the same time, he recalled the magic tools the dwarves had used: devices that fired pieces of metal using the expansion of liquid as it became steam.

What if he used the Spirit of Fire to propel a boulder on a similar principle? What if he filled the sling with it, placed a boulder on top, and detonated it at the moment of release?

As soon as the idea occurred to him, Turan took out several handfuls of Spirit of Fire and piled them into the large sling. He placed a boulder on top to shield the powder from the rain, held everything in place with telekinesis, and rose into the sky.

[□--■---]

Perhaps it recognized his face after their repeated encounters. The serpent, which had been snapping irritably at Maysa as she hovered nearby, glared at Turan with open hostility. It knew he had dealt the most painful blows of any of its current opponents.

The merfolk royals fighting below were visibly heartened by his arrival, too. If the king, who had repeatedly taken the serpent's charges head-on at sea, was their best defender, then Turan, who kept battering its head with enormous boulders, was their best attacker.

Seeing the serpent watching him warily, Turan grinned and detonated the Spirit of Fire as he hurled the boulder.

Heat washed over his hand as the boulder shot forward faster and harder than before. His target was the crown of the serpent's head, the very spot where the Mimic Holy Relic's former owner had buried his hand.