Eternatus was not a Pokémon native to this planet. Like Deoxys, it had come from the depths of space.
However, unlike Deoxys, which had the misfortune of encountering the Rayquaza, Eternatus had arrived on this planet 20,000 years ago via a meteorite, seemingly unnoticed by Rayquaza.
Eternatus was an exceptionally unique Pokémon. To survive, it needed to sustain its vitality by absorbing energy.
Three thousand years ago, in its quest to replenish its energy, Eternatus attempted to absorb the energy particles of the entire Galar region. This act triggered the catastrophic event known as the "Darkest Day."
The energy released by Eternatus formed a massive black vortex, causing numerous Pokémon in Galar to Dynamax or Gigantamax.
These out-of-control Pokémon brought the region to the brink of destruction, nearly leading to its downfall. This was the true origin of the "Darkest Day" calamity.
In the end, it was the legendary heroes of sword and shield who defeated Eternatus, shattering its massive body and saving Galar. These heroes were none other than Galar's legendary Pokémon, Zacian and Zamazenta!
To the Galar region and to Zacian and Zamazenta, who had once saved it, Eternatus was an absolute menace. Its very existence depended on consuming energy, making it an insatiable parasite. This was how Zacian and Zamazenta viewed Eternatus.
"Three thousand years have passed, and it has awakened again?" The cold, blue wolf-like form of Zacian slowly rose to its feet, gazing into the distance. The aura of that calamity was something it would never forget.
"Sister?" Zamazenta emerged from the thick fog, its steady eyes fixed on Zacian. While similar in appearance to Zacian, Zamazenta's red, shield-like form was noticeably more robust.
The relationship between Zacian and Zamazenta was unique among legendaries—they were siblings. However, compared to the more composed Zamazenta, the Crowned Sword Zacian had a far colder demeanor.
"I'll deal with it. That parasite must not be allowed to recover," Zacian said calmly, tucking its rusted sword into its fur and taking a few steps forward.
Eternatus was far too dangerous, and its vitality was too strong. It had to be dealt with swiftly.
Three thousand years ago, Zacian and Zamazenta had shattered Eternatus's body, scattering its fragments across Galar. Yet, somehow, Eternatus had awakened once more.
"Do you need me to come with you?" Zamazenta asked.
"No, it hasn't returned to its full power," Zacian replied. After a few steps, it transformed into a blue streak of light and vanished into the horizon.
Zamazenta watched as Zacian disappeared from view. Zacian's prideful nature was well-known, and Zamazenta had no intention of interfering unless absolutely necessary.
Besides, Eternatus hadn't regained its full strength, and Zamazenta had no doubt that Zacian could handle it.
After all, Eternatus, an alien species, was a Poison/Dragon-type Pokémon, while Zacian was a Fairy/Steel-type.
Poison was ineffective against Steel, and Dragon was useless against Fairy. What more needed to be said? Zacian was Eternatus's natural nemesis, a counter that could utterly dominate it in terms of type advantage.
If it weren't for the sheer power of Eternatus in its Eternamax form, Zamazenta wouldn't have needed to join the fight three thousand years ago…
…
Hammerlocke Stadium.
"Roar~"
Eternatus's dragon-like cry echoed across the heavens, and a dangerous red aura began to emanate from its body. The dark red sky churned violently as layers of black clouds twisted and swirled, forming a massive vortex that engulfed the heavens.
The Darkest Day!
The apocalyptic scene from three thousand years ago was about to repeat itself. The black vortex expanded rapidly, covering all of Hammerlocke and plunging its bewildered citizens into even greater panic.
Yes, having broken free from its prison, Eternatus instinctively began to absorb the surrounding energy.
It was not at full strength, and its energy reserves were depleted.
It needed to replenish itself, especially with the Energy Plant below, which it sensed was brimming with energy.
Three thousand years ago, its body had been shattered by Zacian and Zamazenta, scattering its fragments as Wishing Stars and Wishing Pieces across Galar. Now, it sought to absorb that energy once more to restore its former glory.
"Stop. Do you want to be shattered by them again?" A voice suddenly echoed in Eternatus's mind.
Eternatus paused, and the swirling black clouds in the sky came to a halt.
Shattered by them again?
Eternatus lowered its head, gazing downward. The voice was not unfamiliar—it belonged to the human who had released it. For some reason, Eternatus felt a strange sense of kinship with this human, and as its "savior," it held a certain fondness for him.
But if it didn't absorb energy, how could it recover?
Eternatus tilted its head in confusion, its spotted eyes fixed on Ryuu Shiro.
And at that moment…
A green dragon-like beam shot through the air, striking Eternatus.
It was a Dragon Pulse!
The attack exploded, causing Eternatus a slight twinge of pain. Its dragon-like eyes immediately flashed with danger.
"Raihan!" Oleana's voice rang out with a hint of relief.
Indeed, the Dragon Pulse had been unleashed by Raihan's partner, Duraludon.
Raihan had arrived!
"Here comes the appetizer," Ryuu Shiro smirked, amused by the audacity of attacking Eternatus so recklessly.