So the three of them kept probing the storm-dark sewers, their beam gliding like a minnow over slick stone.

They focused on every crooked nook and drowned cranny. Before long, they found the first mechanism.

A raised brick, lurking underwater at the wall’s foot like a turtle’s shell.

Todo didn’t think; she stomped it like a trigger on a snake’s tail.

“Hey, wait—what if it’s a tra—”

The ceiling yawned open. A torrent dropped like a broken sky and drenched all three of them to the bone.

“—p.”

Yekase raked the water from her hair like shaking rain off willow leaves.

Unease flickered first, then memory surged up—back when she was still Dr Ika. She’d tried to braid Mind Energy with Flash Energy, built a hybrid engine that hummed like a caged comet.

The day before its test run, the boss wandered R&D like a bored cat, got curious, and while Yekase napped, hit start. The foam-wrapped engine overheated in a blink, a campfire gone wild.

And she… slipped out like a shadow in a smoke gust.

By the time smoke stung Yekase awake, the lab lay in ruins, charred like a field after lightning.

Next month’s budget somehow doubled like a sudden fat moon, but a soot-black shadow lodged in Yekase’s heart. From then on, she hated those “what’s this button do?” Bronzebeard types with a cold, lasting hate.

Thinking back now, if she hadn’t cracked and shelved hybrids, the Prismatic War Chariot wouldn’t have shocked her so hard. Maybe the Flashblade System wouldn’t run on pure Flash Energy either.

“…At least… it proves the traps are real. Let’s keep looking.”

She wasn’t sure if she was steadying them, or herself—like patting a trembling bird and feeling her own fingers shake.

With that lesson, they kept netting more mechanisms, one after another like fish flashing from reeds. After trying them all, a mechanical growl rolled from the waterway’s end. The wall split open like a cut in silk.

“Stage cleared!” Todo cheered and splashed ahead like a kid chasing kites.

Yekase and Pulu followed, and stepped into a new chamber.

—WHAM!

The door slammed behind them like a lid on a well.

“Feels bad…” The chill hit Yekase first. The room was coffin-small, a déjà vu from those underground death games where walls are wolves.

High on the wall, a square mouth opened like a black gill.

Water gushed out in a hard white rope.

“Oh crap, it’s the waterboarding tag!”

“Do water park attractions really go this hardcore?!” Pulu’s disbelief spiked like a cat’s fur.

“First, grab the float—Todo?”

“Water torture… death…”

Todo had run in first. She stood at the deepest point like a post in a river, back to them, muttering to the wall.

The air around her felt wrong, like pressure before a storm.

How old is this kid again? Did the horror dressing work too well and spook her stiff? We’re filing a complaint when we get out—

…

“This is a trial.”

Todo spoke without turning.

“…Huh?”

“You grow by crossing life-and-death chasms. Therefore, this is a trial.”

“What are you even saying?”

That tone… it rang familiar, like hearing a temple bell in a strange town.

Before their eyes, her neat black short hair spilled longer, curled, then browned like leaves in late sun. Her frame swelled; from a head shorter than Yekase, she shot up to a head taller, a sapling turned spear.

A flesh-shift.

Mind Energy. She was using Mind Energy.

“I am another self, born of Tōdō Moka’s heart. When she senses crisis, I appear and help her cross.”

“Does swapping in a ringer count as ‘crossing’ though…”

Well, it’s still her own psyche. Call it exploiting a loophole in her own rules.

But that self-styling… the déjà vu sharpened, and Yekase felt a very nasty guess open like a trapdoor.

“Know my name!

Praise my stride!

Witness my victory!”

—Oh no.

It’s her.

Those three lines snapped the last doubt. Yekase almost lost the float, her fingers slick as eels.

The water had risen so high their toes couldn’t find the floor. Yekase and Pulu clung to the ring like driftwood, while Moka’s… something treaded water smooth as a swan and flung her arms wide to proclaim.

“Remember this thunder-loud name!”

Four scarlet characters—literally four visible, tangible characters—blossomed behind her. They slammed the walls in four hammer-beats.

Heavenly! Prison! King!

“Heavenly… Prison…”

Yekase went numb, like snow falling inside her skull.

She knew another place where that codename appeared.

The doorplate on the leader’s office at Unrecognized Consortium X.

The madwoman, that woman, the exploiter, the tigress, the quiet apocalypse—no string of curses could bind her. She took Yekase’s youth, time, spirit, and her—no, not that one.

She’d simply sat in her room and watched the merger win. Then two days later, she ditched subordinates breaking their backs absorbing Triple Calamity’s assets and rebuilding the base, and came to a water park alone to play.

How cruel. How cold and lawless.

“Yekase? You okay…”

Pulu couldn’t tell why Yekase froze and went pale, like a lantern blown out. She shouldn’t be spooked by a Mind Energy demo. Maybe someone who lives with code and circuits can’t stomach the idealist realm and snapped?

“I… I’m fine.”

Yekase shook her head, like shaking rain off a dog.

Even a leader won’t cross a public line and do something crazy to unrelated mundanes. She didn’t drop the Consortium X name—proof enough.

“You two—are you Moka’s new recruits?”

That dragged them straight in by the collar.

Yekase shook her head like a rattle-drum. Pulu didn’t grasp the stakes, but her panic was contagious. She shook too.

“Hmph… just two burdens? Fine. So long as you don’t trip me up, I can haul you out.”

“Uh… how are you hauling us out?”

“Smash that annoying ceiling!”

“Don’t smash it! It’s someone’s attraction!”

“An… attraction?”

A crack showed in her brash mask. “But Moka told me she’s about to be water-tortured.”

The self-styled title vanished like a puff. The “I, this lady” bled away.

“T-That’s her freaking out!”

“Waterboarding” had come from Yekase’s mouth. Great. Keyword-triggered switch, really? What a system…

“Anyway, a water park won’t run truly lethal rides. We can wait until the water kisses the roof and staff come pull us out, but—”

Yekase drew a breath, steady as a diver, and reset.

“I still want to clear it myself.”

“Agreed.”

Pulu let go, slid under like a seal, and resurfaced after ten heartbeats. “Below’s the same as when we came. No change.”

“Then it’s the walls… or the ceiling. Looks monolithic. No seams. Rule out deformation tricks. That leaves—”

“Hey! You dare ignore me!”

Todo—abandoned on the mental stage—flared like a struck match.

Yekase really didn’t want to engage. Her old grudge sat hot on her tongue. But stonewalling would only make her louder. So she leveled her gaze like a blade.

“What’s your name?”

“Heavenly Prison King! I already said!”

“A name, not a codename.”

“…”

She fell silent for a heartbeat, a drumbeat stretched thin.

Pulu didn’t know why Yekase was asking names at a time like this. But her seriousness felt ritualistic, like passing a cup before an alliance.

Never goes to school. Turned the observatory’s entrance into an automatic door in one noon. In a swimsuit but pulls a flashlight like a magician. Industry habits in the wild…

Pulu’s gut said Yekase’s “quirks” weren’t a persona. They were roots showing through soil.

“Michala Aura.”

“Then I’ll call you Mila.”

She—Michala—shook her head, ripples ruffling. “You skip the ready-made ‘Aura’? I don’t get you.”

…What?

Pulu was lost, like a compass near a magnet.

It was just a name, yet “tamed” seemed to pop over Mila’s head in invisible letters.

It only deepened Pulu’s sense that Yekase’s background wasn’t simple at all.

What Pulu didn’t know: Yekase was bluffing to seize the initiative in this negotiation with Mila.

No matter how high Mila peacocked inside the Organization, facing two apparent civilians, she could only play at chuuni bravado.

A leader striking civilians, under her own name, would be judged as bullying. Even if other groups secretly approved, the scandal would be a ready-made casus belli—a declaration waiting to be signed.

As the Heavenly Prison King, Mila did rule many and skim fat from her turf. Yet she too was ruled—by that hulking beast called jianghu code.

These calculations barely cost Yekase a breath. They came as easy as breathing under water.

“Mila, since you’re fluent in Mind Energy, besides embodying text, what else can you do?”

“If I will it, this room will cease to exist.”

“No. Skip that one.”

If you’re that strong, why didn’t you solo Triple Calamity?

“Anything gentler? Like, let the Mind Energy trickle out, evaporate the water… no, that just turns this into a steam room…”

Let Mind Energy… flow.

Flow.

“I’ve got it.”

Yekase lifted her head like a heron sighting prey—toward the only inlet within arm’s dream.

The square black mouth lurked a meter below the ceiling, coughing out water without end.

“That. Right there.”