Most of the Knights of Favonius had already marched into the Stormterror's Lair. However, in order to protect Shen Qin and the Sun's Annihilator, Jean had assigned Noelle and Amber to stay behind with the reconnaissance squad to guard them.
Shen Qin installed the Gnosis into the power system and used his smart wristband to activate the Sun's Annihilator.
Immediately, four stabilizing supports, each over 3 meters long and tipped with wide contact pads. Extended from the turret, lifting the barrel to a height of fifty centimeters above the ground.
This support system was designed to prevent the recoil from embedding the barrel into soft surfaces. It also included flexible components to absorb part of the recoil.
Then, a row of square exhaust nozzles extended diagonally from the rear underside of the turret, capable of dispersing nearly seventy percent of the recoil.
To further counteract recoil, Shen Qin had designed a complex reverse-thrust neutralization system around the breech, allowing the plasma burst's rearward force to be balanced without compromising the projectile's propulsion.
As for why he named the projectile "Dragon-Slayer Round," it was, of course, to suit its debut against a dragon—even though Venti thought the name was a bit too harsh for Dvalin.
"Since Dvalin is essentially a being of Anemo, a name like Wind-Slayer Round would be more fitting," said Barbatos.
With preparations complete, the barrel swiftly adjusted its aim toward preset coordinates. The Dragon-Slayer Round was loaded, and the plasma drive structure converted the Heart of God's energy into glowing plasma clusters, both in the chamber and within the projectile.
Everything was ready. All that remained was for the main character—Dvalin, to make his entrance.
As the Sun's Annihilator began charging. Sucrose, Noelle, and Amber, each bearing a Vision, could already feel the terrifying power building within it. Only now did they start to understand just how fearsome this strategic weapon, designed to combat Archons, truly was.
With Shen Qin's preparations in place, Jean and the others had also formed teams and were heading to the three Light-Guiding Mechanisms to activate them.
Jean and Diluc flew high above, using the scanning function Shen Qin had recently added to their wristbands to locate the three scattered components of the mechanism.
One part had landed on the platform, while another was buried in ruins, and the last had inexplicably ended up at a high elevation.
After collecting all three components, they approached the platform to install them, but a portal from the Abyss appeared before them, and an Abyss Herald of the Tide stepped out to block their path.
Jean and Diluc drew their weapons, warily staring the figure down.
But the Herald ignored their readiness for battle. Instead, it turned its head to gaze at the knights sweeping through the ruins and remarked with admiration, "I didn't expect ordinary people without Visions to wield such strength. It reminds me of Khaenri'ah… This scene is so very familiar."
Jean and Diluc didn't understand its intent and remained silent.
"I was going to try stopping you, but… I realized there's no point. You can't be stopped. So I'll leave it at that." The Abyss Herald finally turned its gaze to them. "I stayed behind just to meet you, and to issue a warning."
"Do not attempt to overturn the current order of Teyvat. If you do, Mondstadt will face catastrophe." Jean and Diluc exchanged glances, unsure what the final sentence truly meant.
"Oh, and before I go, let me give you a parting gift. You wish to save Dvalin, yes? Then allow me to bring him before you now." The Abyss Herald raised his right hand, pointing toward the central spire, his fingertips swirling with malevolent Abyssal energy.
"RRAAAGHHHH!!!" A pained and furious roar echoed from below the spire.
"Well then, farewell." The Abyss Herald slowly retreated into the portal, which vanished behind him.
High atop the tower, Venti had been idly passing the time, when he suddenly sensed a powerful surge of Abyssal energy erupting from within. At the same time, he heard Dvalin's roar.
His expression shifted dramatically. In the next instant, he transformed into wind and teleported a hundred meters away.
With a deafening boom, a violent torrent of corrupted Anemo and Abyssal energy blasted upward from the depths of the spire, shredding the three seals with brute force. Its purplish-black energy spiraled into a vortex above Stormterror's Lair, blotting out the sun.
At the eye of the storm hovered Dvalin, now stained black and violet by tainted blood and Abyssal power. His wings beat the air; the twin horns atop his head had grown grotesquely twisted. His eyes burned with madness and rage.
"He's been further corrupted by Abyssal power and poisonous blood," Venti explained gravely to the others as they arrived. "For the past five hundred years, he's been resisting the blood's erosion, so it never went too deep. But now… they've tempted him to embrace the power within the blood."
"This means he's far more powerful now, and purification will be that much harder."
Jean furrowed her brow. "His strength now… it's worlds apart from when he attacked Mondstadt before."
Their entire operation had been planned based on his previous power levels. But now, that plan was entirely useless.
Dvalin roared and soared through the storm, drawing energy from it. At the same time, the vortex absorbed elemental energy from the air, converting it into power Dvalin could absorb.
"No! He's draining energy to strengthen himself! We have to stop him right now, or no one will be able to oppose him!"
Venti's face went pale as he gathered the Anemo around him, preparing to go all-out.
A storm of pale cyan wind energy gathered around him. Though it contained tremendous power, it brought only a refreshing breeze to Jean and the others nearby.
The Skyward Harp in Venti's hands transformed into a bow. He drew an arrow formed of pure Anemo energy and loosed it at Dvalin.
"BOOM—!"
For a moment, it was as if all Anemo in the world froze. In the opposite direction of the arrow's flight, dozens of meters of ancient ruin were reduced to dust.
But the arrow, which transcended time and space, halted just inches before Dvalin's face, unable to advance further.
"You think I wouldn't be ready for your old tricks?" Dvalin roared. His monstrous claw grabbed the arrow. The pure wind, Abyss, and toxic energy collided, consuming one another—until he crushed the arrow effortlessly.
"Show me your full power, Venti! You won't stop me otherwise! ROOAARRR!!!"
"Damn it, has he really become this strong?" Venti hesitated. If he unleashed his full strength, the aftermath could devastate everyone still in the ruins.
Yet if he held back… they might not be able to stop Dvalin at all.