The war ended months ago.

Gwi-Ma was sealed, his monstrous reign finally brought to a close. No more twisted idols, no more cursed fans, no more sleepless nights wondering who might disappear next. Hunters were given time to breathe. And you, the one who risked everything to end it, were granted a long, quiet break from the chaos.

Everyone believed the demons were gone.

But one stayed behind.

Mystery.

Not bound by Gwi-Ma's control, not forced to follow orders anymore, he was just... there. A demon without a master. Without a purpose. For a while, he didn't know what to do with himself. He didn't belong in the demon realm anymore. But the human world wasn't made for creatures like him either.

So he watched.

He followed you. Not closely enough to be noticed, but never far. Perched on rooftops, hidden in alleys, crouched behind trees as days turned into weeks. He told himself it was curiosity. Then safety. Eventually, he stopped lying to himself. It was instinct. Something deep in him refused to walk away.

He couldn't.

But he wasn't the only one watching.

The man came out of nowhere. At first, Mystery didn't think much of it. Just a stranger walking the same street. But the man always showed up. Wherever you went, he was there—too casual to be coincidence. Standing across the road. Sitting alone at cafes. Waiting near the station exit. Always a little too long. Always with eyes that lingered.

Then one night, Mystery saw him do something more.

The man crouched near your front door, watching carefully as you keyed in the lock code. He didn't do anything else. Just watched, smiled to himself, and walked away like it was a game.

Mystery could've ended it then. He could've dragged the man into an alley and made sure he never saw daylight again. But instead, he followed.

The next time, you were out.

The man returned.

He slipped inside easily, like he'd practiced the code a hundred times. Mystery followed in silence, invisible, keeping to the shadows of the apartment across the street. The lights were off inside, but that didn't matter to him.

The man wandered. Touched things. Ran his fingers along the shelves. Took out one of your oversized jackets and wore it in front of the mirror. Lay on your bed like he belonged there. Even took photos of himself with your undergarments, smiling like it was all some twisted fantasy.

Mystery watched with clenched fists.

Then the man opened the closet and stepped inside, leaving the door cracked just a little. Just enough to see through. He pulled out his phone. Opened the camera. And waited.

Mystery held himself back from attacking, knowing you would come home soon. He was sure that if he attacked now, he would also get himself reported to the authorities.

The door opened. Footsteps. A tired sigh. The keys hit the table. You were humming softly—something from the radio maybe. You looked relaxed. Unaware.

Mystery had already entered.

He stood behind the front door, silent and unseen. He didn't breathe. Didn't blink. Every instinct in his body screamed to kill the man in the closet, but he didn't move.

Not yet.

You turned your back to the hallway, reaching for your top, tugging the hem to undress.

The closet door creaked ever so slightly.

Inside, the man raised his phone. Camera already recording.

That was enough.

In one swift motion, Mystery dropped his invisibility and stepped forward. His arm wrapped tightly around your waist and he pulled you against him, spinning you away from the line of sight. His long cloak dropped down, dark and heavy, covering your body entirely.

You gasped, tense, completely caught off guard.

He didn't let go.

"Don't move," Mystery said, voice low, quiet but cold. "He's in your closet."

His eyes were locked on the crack in the door. No blinking. No flinching.

And from the other side, the man held his breath.

Mystery didn't look away from the closet. His body stayed still, solid as stone, cloak still wrapped tightly around you.

The man inside was panicking. You could both hear it now—the slight hitch in his breath, the creak of a boot shifting on the wooden floor.

Then Mystery raised a hand.

Dark energy pulsed at his fingertips, low and quiet like a storm just under the skin. With a flick of his fingers, the closet door burst open. A force, unseen but undeniable, yanked the man out by the chest. His body lifted off the ground, legs dangling, phone slipping from his fingers and crashing to the floor.

He hovered in the air, choking, clawing at his neck even though there was nothing physical around it.

Mystery turned his head slightly toward you, his voice calm but laced with something dark.

"What should I do with him?" he asked. "Say the word."

The question wasn't a bluff. One wrong answer and this man would vanish without a trace.

You stepped out of Mystery's cloak, eyes wide, hands trembling but composed. "Put him down. Just—not gently."

Mystery obeyed. The man dropped to the floor with a heavy thud, coughing, eyes wild with terror.

Within seconds, you had grabbed a length of cable from a drawer and started binding the man's wrists. Mystery held him still without touching him, using his powers like invisible ropes. You tied his ankles next. Gagged him with a scarf. It wasn't perfect, but it worked.

You quickly called the police. Later, they came and dragged the man into their car, driving to the station.

You filed a report, explained what happened and shared the footage from your home CCTV cameras. Mystery stayed hidden in the shadows again, watching from the rooftop as flashing red and blue lights carried the man away.

When it was over, you walked back into the now-silent condominium. The adrenaline was fading. The fear was still there, clinging to the walls.

And Mystery followed you in.

He didn't speak right away. Just stood near the door, eyes flickering with leftover rage, posture tense like he was still ready to strike again if needed.

You turned to him. "You saved me."

Mystery blinked, caught off guard. "It's nothing. He's a bad person."

You chuckled softly. "How ironic. You're a demon, but you saved me from a bad person. I still don't understand how you didn't disappear like the rest of the demons, but I see you have no bad intention, so I won't kill you right now." There was a little hint of playfulness in your tone. The sides of Mystery's lips slowly curved into a smile.

"But seriously, you really saved me back there. Is there anything I can do to return the favor?"

Mystery hesitated.

He looked down, then looked up again, something different in his gaze now. Not rage. Not coldness. Just honesty.

"Let me stay," he said. "Here. With you."

You blinked. "Here? In my house?"

"I'll not bother. I protect. Always. No place for me... only here. I don't want to leave."

He looked serious. Almost vulnerable beneath the sharp edges.