The Curiosity of the Hydro Eidolon

 When suspicious green mist wafted over Fontaine's central fountain, the brass bell of the blue-roofed shop chimed like a clear spring. A little girl with a crystal hairband tiptoed to the counter, water droplets from her hair forming tiny whirlpools on the oak surface: "I want that blue box. Can I pay with seashells?" 

Lumine accepted the damp shells, each etched with ripples from the Fountain of Lucine. "Little one, this cleaning box might—" 

"I'm Lulu." The girl's fingertips brushed the shelves, droplets forming leaping dolphins in the air. "I live by the rainbow waterfall." She chose an indigo box labeled "Cleaning Guardian," and the purification pearl inside leapt out, transforming into a fish-shaped water orb that devoured the dust on the shelves. 

Kazuha crouched to inspect the "customer," sniffing lightly. "The scent of the eastern Lucine tributary? Last week's water tests showed excessive dissolved oxygen there." Lulu backed away nervously, spilling lemonade that morphed into jellyfish shapes mid-air, mistaken by patrolling Melusines as new pollutants. 

"Alert! Unidentified gelatinous lifeform detected!" The guard's mechanical claws sprayed cleaning foam, but the jellyfish playfully ensnared her head. Lulu hid behind the shelves, her crystal hairband glowing faintly. 

Late at night in Fontaine Plaza, Lulu stepped barefoot into the foul-smelling fountain. The moment the purification pearl touched the water, an emerald geyser shot thirty meters high, attracting Blubberbeasts who danced in rainbow mist. Morning joggers were startled to find: 

Twelve historical statues had been cleaned, even the Geo Archon's dragon scales gleaming. 

The mist changed colors with emotions—couples arguing were drenched in acid rain. 

Blubberbeasts learned to write "Feed Me" on the water's surface with their tails. 

The fountain played variations of *Light Rain Ripples*, notes dancing with the spray. 

Sigewinne rushed over with a medical kit: "Whose prank is this?!" only to be dyed blue by a sudden spray. Wriothesley stifled laughter nearby, his warden uniform now polka-dotted. 

Furina was filming *The Purity of a Spring-like Nation* by the fountain. As she recited "the water city blessed by the gods," the water formed an arrow pointing at her cream puff. The purification pearl broadcast: **"Sugar levels detected! Initiating forced cleaning!"** 

The water chased the Hydro Archon through the streets, finally washing her into a bakery's freezer. "This is blasphemy!" Furina roared, crowned with ice cream, still clutching half a puff. Charlotte captured the moment for *The Steambird*: *"The Ultimate Showdown: Deity vs. Dessert."* 

Lulu giggled in the crowd, her hairband reflecting a faint image of Rhodeia's true form. 

"This is a goldmine!" Kazuha leaned over the revitalized fountain, only for his net to be ensnared by watery serpents. The mist formed ancient Teyvat script: **"Sell nature's gift, and you'll be pickled fish."** 

Lumine stifled a laugh as the shopkeeper dangled upside-down: "Told you not to mess with Hydro Eidolons." Her elemental scanner showed Fontaine's water systems at 300% activity—even Meropide's bathwater smelled of jasmine, prompting inmate complaints: "We smell like flowers! Too girly!" 

A week later, the plaza hosted a purification festival. Lynette's mechanical fish performed water-screen magic, while Lyney's flaming roses danced with purified streams. Lulu sat atop the tallest statue, Blubberbeasts offering macarons like tributes. 

Neuvillette tossed an "Honorary Water Purifier" medal into the pool, which transformed into a silver fish swimming away. Furina retaliated with a custom cake, only for the purification pearl to slice it into 888 pieces for the crowd—each flagged with "Moderate sweets are healthy." 

"Unfair!" The Hydro Archon stomped, her hair droplets forming otter-shaped water creatures offering cake crumbs. 

The next day's *Steambird* headline: *"Mysterious Water Spirit Heals Mother River!"* featuring Lulu dancing with Blubbeasts. Unnoticed in the corner, Rhodeia smiled in mist form. 

The blue-roofed shop released a special "Purification Box," its instructions written in ripples: **"Use for salvation, not greed."** Kazuha lamented over sales reports: "The most profitable series, and we can't mark it up? Where's justice?" 

At the fountain's bottom, purification pearls split into countless offspring, swimming toward rivers across Teyvat. Three days later, Xiangling fished a glowing pearl from Liyue Harbor: "What a pretty fish eye! Perfect for boiled fish tonight!" 

Chongyun hesitated as the "fish eye" boiled in spicy broth, only for the pearl to leap out, purifying the soup into mountain spring water. Xingqiu laughed: "This dish should be called 'Pristine Water'!" 

Under the moonlit fountain, Rhodeia's true form caressed the water. The pearls shimmered like stars, forming an ancient prophecy: **"When humans learn reverence, springs will sing."** 

Across the way, in the blue-roofed shop's window, mechanical otters slept clutching mini pearl plushies. Lumine wrote in the logbook: **"Today's 'Cleaning Guardian' sales: zero—because everyone who opened a box heard the water's gentle warning."**