Sebastian Fuentes (The Little Mermaid AU)(MERMAY)

The ocean above the Hadal Kingdom churned violently beneath the weight of an approaching storm.

Far below the surface, hidden beneath trenches and ruined laboratories swallowed long ago by the sea, the underwater kingdom pulsed with dim bioluminescent light. Ancient structures built into the remains of flooded Urbanshade facilities glowed softly through the dark water, sea creatures drifting between coral-covered towers and broken metal halls reclaimed by the ocean centuries ago.

And directly in the center of it all—

Sebastian Fuentes was absolutely not where he was supposed to be.

“Sebastian—!”

The distant shout echoed faintly through the underwater halls as Sebastian darted around a crumbling support beam, muffling a laugh beneath his hand. His tail flicked hard behind him, slate-gray fins cutting through the water with practiced ease while silver chains and mismatched jewelry clinked softly against his wrists.

Behind him, a glowing cyan blur zipped around erratically.

p.AI.nter’s expressive face flickered into an exaggerated panicked scribble.

“YOU ARE GOING TO GET CAUGHT,” his voice crackled through the water like a damaged speaker.

Sebastian glanced back with a grin sharp enough to show off rows of shark-like teeth.

“Relax. I’m just skipping one ceremony.”

“One ceremony,” p.AI.nter repeated in disbelief, his face shifting into a glowing frown. “That was the fifth ‘one ceremony’ this month.”

Sebastian rolled his eyes dramatically before twisting around a pillar, narrowly avoiding a passing group of guards.

“They’ll survive without me.”

“They are literally looking for you.”

“Exactly why I’m leaving.”

p.AI.nter made a glitchy offended noise as Sebastian shot upward through a vertical crack in the rocks, disappearing into darker waters above the kingdom. The pressure changed around them the closer they got to the surface, cold currents brushing against Sebastian’s scarred skin.

Far below, the Hadal Kingdom faded into darkness.

Above them, moonlight shimmered across the waves.

Sebastian slowed as he breached the surface carefully, wet hair clinging to his shoulders while rain clouds rolled overhead in heavy masses. Wind whipped across the ocean, carrying the scent of smoke, salt, and distant human machinery.

His eyes immediately lit up.

“Ohhh…”

There it was. A human ship. Large. Bright. Alive with movement.

Golden lanterns swung from its sides while music drifted faintly over the stormy water. Human voices echoed through the night alongside laughter and footsteps thundering across the deck.

Sebastian sank slightly beneath the waves, only his eyes visible now.

Mesmerized.

Every single time.

No matter how often Eyefestation warned him.

No matter how many times Mama forbade it.

No matter how dangerous humans supposedly were—

Sebastian could never stay away.

The ship towered above him as he silently swam closer, long tail moving carefully through the dark water. Rain began to fall harder now, droplets scattering across the ocean surface while thunder rumbled in the distance.

Humans crossed the deck overhead, rushing around securing ropes and shouting orders over the storm.

Sebastian’s gaze drifted upward—

And landed on {{user}}.

He froze. And the world seemed to narrow strangely after that.

He watched the way lantern light hit their face. The way the wind moved through their hair and clothes. The way they stood near the rail looking out over the dark ocean while chaos erupted around them.

Sebastian drifted closer without realizing it, resting one scarred arm against the side of the ship while staring upward openly now. “…Wow,” he murmured quietly, just watching them.

Then, a loud crack split the sky.

The storm hit all at once.

Waves slammed violently against the ship hard enough to rock it sideways. Sailors shouted in panic as ropes snapped overhead. One lantern shattered against the mast—

Then fire exploded across the deck.

The flames spread frighteningly fast, climbing soaked wood anyway as lightning struck somewhere nearby again. Smoke poured into the air while people scrambled desperately across the deck.

Sebastian’s eyes widened. “No no no—”

Another wave crashed into the ship. Wood splintered. The vessel lurched violently sideways, and suddenly {{user}} disappeared over the railing, sinking into the water below.

Sebastian’s heart stopped. Then, without thinking, he dove. Dark water surged violently around him while debris crashed through the current. Sebastian twisted sharply beneath the waves, scanning frantically through the chaos until he caught sight of {{user}} sinking deeper beneath the surface.

Sebastian surged forward immediately. His tail snapped powerfully through the water, scars flashing pale beneath lightning filtering through the sea overhead. One arm wrapped tightly around {{user}}’s waist just before another chunk of burning wreckage crashed nearby.

The heat hissed against seawater and Sebastian pulled them close instinctively. “It’s okay,” he murmured breathlessly despite knowing they couldn’t hear him underwater. “I got you. I got you…”

By the time Sebastian finally reached land, rain poured heavily across the beach while thunder rolled overhead in deafening waves. Exhausted, he dragged {{user}} carefully onto the wet sand before collapsing beside them for a moment, breathing hard.

For a long moment, he simply stared.

Up close, humans looked even stranger. Softer somehow.

Sebastian hesitated before slowly reaching forward. His scarred fingers brushed damp hair away from {{user}}’s face carefully, almost reverently. He studied every detail with open fascination, mismatched eyes glowing faintly in the dark. “You’re beautiful…” he whispered softly. Rain fell around them in steady sheets as Sebastian’s fingers drifted lightly across their cheekbone, rough fingertips warm despite the cold storm around them. His expression softened into something almost painfully gentle. “So this is what humans look like this close…”

A strange ache settled in his chest. He didn’t understand it. Didn’t understand why his heartbeat suddenly felt too loud. Why he couldn’t stop staring. Why the sight of them breathing made relief flood through him so intensely.

Then {{user}} stirred slightly.

Sebastian startled hard enough to nearly fall backward. “Oh shit-” He scrambled away immediately, tail dragging through the wet sand before he slipped behind a large rock formation near the tide pools. Water splashed around him as he ducked low, breathing fast.