The root of all this began—often enough—from the smallest seed.
Ten years ago.
In the Alola Region, not long after Melemele Island was occupied by a mysterious monster, codenamed "UB05: Glutton King"—the Ultra Beast Guzzlord—
Disappointed in humanity, the island guardians attacked the Glutton King, but couldn't use Z-Moves.
The result was inevitable—the Glutton King devoured even moves themselves; the Ultra Rangers' resistance was meaningless.
People fled Melemele Island and resettled on other islands.
But this was only the beginning. Rather than learn, humanity only doubled down on developing what remained—resourcefully exploiting the other three islands.
Poni Island was no exception.
The island guardians, disheartened by endless land development, disappeared one after another.
Z-Moves ceased functioning altogether.
Taking over the rights to develop Poni Island was the Rainbow Happy Resorts Company, which rapidly rose to become one of Alola's top corporations after Melemele's fall—even surpassing the Aether Foundation.
President Viren was violent and ambitious—his style more like a thug than an executive.
For profit, he would stop at nothing, breaking promises without hesitation.
In truth, it was by virtue of this style that the Rainbow Happy Resorts rose to the top.
During Poni Island's development, Viren saw enormous potential in energy exploitation—building countless power plants.
Using leftover technology from the dissolved Aether Foundation, he succeeded in opening Ultra Wormholes, summoning hordes of Xurkitree.
Through his own custom tech, these Ultra Beasts could be controlled. With power plant energy, the Xurkitree became overwhelmingly powerful.
Soon, Viren crushed all opposition by force and seized complete control of Poni Island, launching wild development.
Pollution grew worse and worse.
By the time Tapu Fini, who had secluded itself out of despair, awoke from its cyclical slumber—
It was too late.
Human advancement was far swifter than these "immortals" could have imagined.
When Tapu Fini saw blackened seas, sunless skies, and the ravaged land of Poni, rage took it straight to the power plant.
Waiting for it—were Xurkitree swarming every mountain.
Each one charged with electricity rivaling even Tapu Fini's serious attacks.
Even if only momentarily, when faced with masses of suicidal, controlled Xurkitree, and with polluted ocean currents and nature itself failing as power sources—Tapu Fini was doomed to lose.
Unlike the battle-loving Tapu Koko, Tapu Fini was never eager to fight. So, naturally, it lost.
After that, no one could stop Viren or his Rainbow Happy Resorts from continuing.
In a blink, Poni Island became what Lucas saw on his arrival.
Tapu Fini's injuries never fully healed; its wellspring of power gone, it could only hide.
Two years ago, it found a Poké Egg washed up on a secluded Poni beach, miraculously still alive despite the black waves.
Believing all life on Poni was gone except itself and Xurkitree, Tapu Fini was moved nearly to tears. Without hesitation, it embraced the egg, sealed its shell, and hoped its own warmth and the egg's shell could protect it from pollution.
Just recently, the egg hatched—yielding Popplio. But with sparse resources and vile conditions, Popplio's life hung by a thread.
It was then that, miraculously, Tapu Fini established a link with its counterpart from another world. But, unable to trust strange humans due to past betrayal, Tapu Fini refused their offer of help.
Her counterpart ignored this and simply sent Lucas over.
Everything that happened after is what led to now.
Sofu explained this history to Lucas—like an omniscient bystander, as though he'd seen it all unfold.
Lucas fell silent for a moment after the tale.
That Viren guy—he sort of remembered.
He was a minor villain who popped up a few times in Sun & Moon. First appeared coveting Kiawe's family ranch, tried to buy it, then turned to shady tricks, which led to a weird Pokémon battle—his Electivire lost to Kiawe's Alolan Marowak.
He wasn't done, though, summoned demolition machines by phone to try and forcibly evict people, but Officer Jenny stepped in.
Later, he even had a "Revengers' Team" in the Battle Royal, scheming to beat Professor Kukui (disguised as Masked Royal) and Ash.
All in all, a low-rent villain whose plot always failed.
Lucas never expected him to accomplish this in a parallel world.
Sofu, visibly concerned, looked at the silent Tapu Fini, and spoke up again: "Tapu Fini's fog allows us—those who've passed on—a fleeting return to this world."
"My words are compiled from the countless souls who perished on Poni these ten years, with Tapu Fini's input as well."
At the mention of "perished souls," Lucas noticed Tapu Fini trembling—it deeply blamed itself.
As the guardian, it ended up protecting nothing.
Guilt and self-reproach must have consumed Tapu Fini for a decade.
Lucas glanced at Tapu Fini, but instead of assigning blame, he preferred to focus on the present.
After a clearing of his throat, Lucas spoke up: "I roughly understand."
"In other words, what stands before us is a huge swarm of Ultra Beasts—Xurkitree, number unknown—plus the real culprit, Viren, president of the Rainbow Happy Resorts?"
"Correct," Sofu nodded gently, then added, "Individually, Xurkitree may not be overwhelming, but their energy is ample, and their numbers are vast."
That was the greatest challenge.
Lucas had already faced one earlier.
Its explosive power was so fierce that even a Dragonite wouldn't dare to take it head-on. In a way, Tapu Fini's loss was not unearned.
Type disadvantage, numbers, and energy support—all on the enemy's side.
In game terms, this was nightmare-level difficulty.
Tapu Fini should be proud she didn't simply get herself captured.
On Lucas's side, only Luxray, Swampert, and Dragonite could take the field.
Three Pokémon against perhaps a thousand Xurkitree—not even Lucas could say he had the upper hand.
Not to mention the oxygen problem—
Unwilling to give up, Lucas tested the waters: "Do you still have any power left to temporarily purify a limited area?"
If so, his side might not have to hold back.
If not, their power would always be hobbled—and just swapping portable oxygen mid-battle was enough to give Lucas a headache.
He wouldn't rush into a nearly unwinnable situation lightly.
Tapu Fini, embarrassed, shook her head and fidgeted.
She didn't even have strength left to purify Popplio's pollution—much less maintain large-area purification.
Lucas wasn't surprised, already prepared. After thinking it over, he decided—Viren was the key.
Catch the ringleader; the mob would scatter. As long as Viren fell, the Xurkitree couldn't take over.
They could send the Xurkitree back to their dimension one by one, if needed.
But before that—
Lucas looked at Tapu Fini and smiled: "May I examine you?"
With his half-baked medical skills, he gave the suddenly bashful Tapu Fini a check-up.
Conclusion:
Compared to Popplio, Tapu Fini's state was much better. Her semi-legendary body barely suffered any environmental corrosion.
Her main problems were:
Unhealed injuries from her defeat by the Xurkitree, as Sofu had mentioned.
Lack of overwhelming energy: the sea and nature sources were poisoned, so she could no longer compare with, for example, the unaffected Shiny Tapu Koko on Melemele.
Lucas did think of getting help from the other guardians on the other islands.
But according to the system, those three had long left Alola.
Only the single-minded Tapu Fini persisted here.
"Well, treating your wounds comes first."
Lucas, like a certain blue robot cat, produced a bottle of "Life #1."
But this was his last bottle—any more, and even he couldn't have provided.
The mixture—crafted from secret herbs—should work wonders for Tapu Fini's wounds.
Tapu Fini studied the odd-colored liquid for two seconds—then, to Lucas's shock, gulped it down in one go.
Lucas didn't even have time to bait her with "Don't you want Popplio to have a good home?"
Normally, "Life #1" would start working in ten minutes to half an hour.
Popplio's frail constitution took longer to recover.
But here, just over a minute later, Tapu Fini's pale complexion turned healthily rosy.
(Of course, her skin was black; it was hard to tell if you didn't look closely.)
"Lahee."
Feeling the change, Tapu Fini stared at Lucas in astonishment.
The recovery effect almost matched Tapu Lele's scale powder—and was more effective in some ways!
Her long-standing wounds healed rapidly.
"Ohoh—"
Ghostly Sofu stroked his beard, amazed.
This Lucas was truly reliable.
With him here, maybe Tapu Fini could finally be freed from this decade of pain.
Tapu Fini absorbed most of the medicine's effects over five minutes.
For the first time in ten years, she felt light and free—almost as if she could swim laps around Poni Island again.
Only—there was no longer a beautiful ocean worth swimming in.
Though she couldn't shroud mountains in fog like before, at least she could use some of her old powers again.
Not as strong as before, but it'd do.
Ultimately, most of her strength originated from nature and the sea.
Tapu Fini couldn't wait—she had Lucas release Popplio, planning to use her freshly restored, "purifying water" ability to cleanse Popplio.
That way, even if things failed, she could still entrust Popplio and Lucas to her counterpart.
…
Meanwhile, at the Ruins of Hope—
With a roar of helicopter rotors, Viren and his sycophantic underlings arrived.
"The Ruins of Hope—1146 disappeared here?"
Despite their protective suits, Viren's vulgar gold chain and tooth sparkled.
A subordinate finished checking the site: "President, there are signs of battle here. It seems the enemy escaped by digging a tunnel."
"Didn't need you to tell me, I can see that with my own eyes."
Viren replied irritably, but was thinking hard.
Now that he'd found the previously secret Ruins, he found the place itself rather uninspiring—barely better than the outside.
So much for the famous Ruins of Hope.
He was far more interested in Tapu Fini and the intruder aiding her.
Someone dared invade Viren's territory? He'd teach that fool what regret meant.
Unwilling to waste time, Viren, usually content to rule from behind the scenes, decided to take the field in person today.
"To the power plant—mobilize 800 Xurkitree. I want the island turned over if needed. Find them and bring them to me!"
With a savage grin, Viren stomped into the helicopter, flanked by Xurkitree.
The island was nearly done for anyway. If it broke apart and sank—he'd just find somewhere new.