Chapter 136: The Thunder Emperor
Let us turn the clock back a short while.
To the time when Ryu and Zekkai had shut themselves inside the archive room.
“……………”
The Thunder Emperor slowly opened his eyes.
His consciousness rose from darkness like a man surfacing from the depths of a silent sea. His vision was blurred at first, his ears ringing faintly, but the sharp pride in his gaze had not dimmed in the slightest.
As expected of an S-Rank adventurer.
Even though Ryu had held back, he had taken that attack head-on—yet in such a short span of time he had already regained consciousness. For an ordinary man, that blow would have meant certain death. But he was no ordinary man. He was the kingdom’s representative, the wielder of the world’s strongest lightning magic. His reputation was not an empty title.
When he tried to move the body embedded in the wall, a fierce pain shot through him.
“Ghk—!”
Pain flared across every nerve.
(Agony… all over my body… Why…?)
Clenching his teeth against the throbbing torment, he forced himself free from the cracked wall. Dust and fragments of stone rained down around him as he staggered forward.
(First… a high-grade recovery potion…)
He reached into his item bag, withdrew a crystal vial filled with shimmering liquid, and drank it down in heavy gulps.
Warmth spread instantly through his body. Open wounds sealed before his eyes. The cracked ribs beneath his skin knit themselves back together with faint, uncomfortable pops. His breathing steadied.
“…Haaah.”
He exhaled deeply and forced himself to think.
(What exactly happened to me?)
An empty prison cell. Shattered walls. Knights sprawled across the corridor, drenched in blood.
“Ah—!”
(That’s right. I encountered a new intruder who rescued Zekkai… and in the blink of an eye, I was knocked unconscious…)
Yet he had no recollection of how the attack had come. No sensation. No visible motion. Ryu had simply been too fast to perceive.
“…I—an S-Rank adventurer representing the kingdom, the strongest lightning mage in the world—was knocked out in a single instant…? Absurd. That was clearly beyond human limits… Which means…”
His expression twisted with fury.
(Some underhanded trick… some new magical device… He must have cheated…!!!)
“You coward!”
He smashed his fist into the wall, reducing it to rubble.
(If he rescued Zekkai, then that intruder is from the accursed Empire… No, a dog. Filth unworthy of life. There’s no need to capture them anymore. I’ll toy with their lives using my lightning… and in the end, I’ll kill them slowly and cruelly.)
With humiliation burning in his chest and rage boiling at the rescue of Zekkai, the Thunder Emperor cloaked his legs in azure lightning and dashed down the corridor in pursuit.
As he ran, a scream echoed from the direction of the archive room.
“Don’t tell me… they intend to steal the airship’s blueprints?!”
(If Zekkai escapes and the blueprints are taken as well, my name will be tarnished… I must hurry…!)
When he arrived, however, he found only the corpse of a researcher and a cluster of security knights gathered around it.
“Thunder Emperor-sama…?”
“It’s Thunder Emperor-sama! He heard the commotion and came to assist!”
He barked a single furious demand.
“WHERE ARE THEY?!”
The knights flinched.
“W-We don’t yet know the culprit’s whereabouts…!”
“We believe they are still nearby…”
“Tch… useless incompetents…!”
Then a scream rose from the direction of the airship.
(There…!)
By now, his mind was consumed entirely with killing the enemy. The safety of the airship or its blueprints had been pushed aside.
—and then—
“I FOUND YOU!!! You imperial dogs!!!”
◇◇◇
Ryu had been stepping in and out of the airship, deliberately provoking the kingdom’s knights, when at last the Thunder Emperor appeared.
Judging by the madness in his eyes—
(He’s completely focused on killing me and Zekkai.)
Crimson rage burned across the Thunder Emperor’s face, and azure lightning coiled around his legs.
(Oh? He can wield Azure Lightning. Impressive. As expected of an S-Rank representing a nation… Though in his case, he probably cares little for his homeland—or even the Adventurers’ Guild.)
From the moment Ryu first saw him, he had judged the man accurately: not one to feel gratitude or pledge loyalty, but a shallow sort who sought power solely to build his own wealth and fame. And indeed, that assessment had proven correct.
Even now, the Thunder Emperor had rushed here not for the kingdom’s sake, but to protect his own reputation—and to avenge the humiliation of being knocked unconscious.
“Unfortunate for you. There’s an airship here—and countless knights. You were planning to run wild, weren’t you? The situation favors us—”
Before Ryu could finish—
“Go. Violet Lightning Spears.”
Five spears of crackling violet lightning shot forward.
Between Ryu and the Thunder Emperor stood the kingdom’s knights. So of course—
“AAAAAGH!!!”
“Are you alright?!”
“Fall back! Retreat!”
The spears pierced straight through them and continued onward.
Ryu twisted his body to evade, but the spears curved violently midair.
(Your torso. I’m not kind enough to kill you in one strike.)
Yet Ryu calmly caught one of the spears in his hand.
“Hmm. Violet Lightning Spear. A fine spell.”
He crushed it, and it vanished.
The Thunder Emperor frowned.
(Another strange trick… What underhanded mechanism is he using?)
“When you knocked me unconscious—and now—what kind of cheating are you using? Has the Empire developed some body-enhancing magic device?”
“You don’t remember what happened?”
“…Regrettably. I lost consciousness before I could perceive it.”
(So he didn’t see the Black Lightning. Might not even know it exists. Well, that’s fine. Being able to wield Azure is impressive enough. As expected of S-Rank.)
When he had knocked him out, Ryu had been cloaked in Black Lightning. But just now, crushing the spear had required nothing more than his natural lightning resistance and the raw physical strength of a dragon.
“By the way, your spell severely injured several kingdom knights. It even punched holes in the kingdom’s precious airship. Is that acceptable?”
“They are necessary sacrifices. There are tens of thousands of knights. And the airship can be rebuilt.”
“If you say so.”
The knights, however, were less convinced.
“Thunder Emperor-sama… we ask for at least some consideration…”
“We are expendable, but at least spare the airship…!”
“Silence. It is unthinkable that you would speak to an S-Rank in such a manner. If you understand, withdraw immediately and do not interfere.”
“…!”
Overwhelmed by his pressure, the knights retrieved the wounded and retreated.
“Now then. It is time for you to die.”
More than a hundred Violet Lightning Spears materialized above his head.
“Try hitting me.”
“Hmph. No matter your tricks, before my magic you are nothing but dust. I will make you understand that.”
Opportunities to witness advanced lightning magic from another were rare. Ryu felt a flicker of anticipation.
At last—the true battle began.
The spears rained down. Ryu utilized the vast underground space and even the airship itself as obstacles, evading with fluid precision.
(Not bad. For scum, you wield excellent magic.)
“If that fails, I shall show you ground-tracking and aerial-tracking lightning magic. Come forth—Thunder Beast. Thunder Bird.”
Countless lightning constructs surged toward him.
(Outstanding. I’d love for my students to see this.)
Ryu dashed freely, but the pursuing lightning devastated everything in its path—the airship, the retreating knights, even distant researchers observing in horror.
The captain of the knights shouted in panic.
“Damn it! This battle is beyond us! All units—protect the noncombatants and head for the exits!”
“Sir!”
The Thunder Emperor paid them no mind.
(Still not enough…? Very well!)
“I shall show you true lightning magic! Lightning Prison!”
Lightning surged through the ground, placing the entire underground chamber under his dominion.
“This is my world now! The world of lightning that sank even Zekkai!”
The chamber trembled violently. Lightning raged everywhere.
The Thunder Beasts and Thunder Birds halted and merged into a massive sphere of crackling energy.
“Manifest! Thunder God Dragon—Fafnir!!!”
A colossal blue dragon of lightning descended at his command.
Faced with magic beyond expectation, Ryu murmured—
“This is…”
“Terrifying, isn’t it? Afraid? If you wish to beg forgiveness, now is your last chance. Kneel!”
The Thunder Emperor sneered.
“Though I shall show no mercy! Slaughter that imperial dog, my dragon Fafnir!!!”
The azure dragon folded its wings and dove.
“I will erase you without leaving even ash! Ahahahaha!”
“………………”
Ryu gazed blankly at the descending dragon.
The Thunder Emperor’s words echoed in his mind.
“I shall show you true lightning magic!”
(True lightning magic… huh.)
For the first time, Ryu entered a true battle stance and placed his hand upon Kurikara.
◇◇◇
The masterpiece blade Kurikara, left behind by Sanjo Kokaji Munechika, possessed a single ability—mutation.
In simple terms, it could adapt to its surrounding environment and transform itself accordingly—an ability unique to adamantite.
It had once adapted to the illusory world created by Dragon King Bahamut, transforming its blade into a gateway to that realm. It had done so without even needing its master’s command.
Though timing had not always favored it, it was undoubtedly worthy of its title as a supreme blade.
And would Ryu ever neglect such a magnificent ability?
No. Never.
He would not allow it to go to waste.
Kurikara could adapt to only one environment or command at a time. Thus, if he were to exploit its power, he must choose the ultimate transformation.
The answer did not come easily.
One day, he had been troubled.
He could wield Azure Lightning to create an Eastern dragon. But he could not create one with Black Lightning.
The reason was obvious.
The control required was too immense.
It was simply his own lack of power. Nothing more, nothing less.
And then—
In that moment—Ryu had an epiphany.
If Kurikara became the mana core of a Black Dragon… and mutated into the dragon itself—
◇◇◇
Ryu drew Kurikara and issued his command.
“Come forth, Black Dragon—
—No.
Kurikara Dragon King.”
And the black Eastern Dragon King answered the Dragon God’s call—manifesting into this world.
