Transmigrated as the Villain Between the Heroine and the Villainess

The voice in Marius's head was not a suggestion. It was a promise. A dark, soothing balm offered to a soul raw with grief.

He could feel its energy, a tendril of pure, ancient darkness coiling around his shattered spirit. It wanted in. He could feel its presence, waiting just beyond the veil of his consciousness.

A sharp, searing pain shot through him. Marius fought it, his own will a desperate, flickering candle against a hurricane. He resisted.

Then, the memories came. Not as fleeting thoughts, but as vivid, living moments.

He saw Martha in their garden, her hands covered in dirt, laughing as she held up a misshapen carrot.

He saw her in the kitchen, a smudge of flour on her nose, scolding him for trying to steal a taste.

He saw her anger, her face flushed after he'd gotten into a duel at the academy, her hand smacking the back of his head before she tended to his wounds.

He saw their arguments, their love, their quiet moments reading by the fire. He saw their entire life together, a world of warmth and color.

Then, she appeared in his vision, clear as day. She was smiling, that sad, tired smile from her last days.

'You got this, Marius,' she whispered, her voice a phantom on the wind. 'I've waited for so long. I can't wait anymore.'

Seeing her, hearing her, it broke him. His resistance shattered like glass. The dam of his will burst, and the dark energy flooded in, pouring straight into his soul.

A scream ripped from Marius's throat. It was a sound of pure, inhuman agony that echoed through the entire forest, silencing the birds and making the very trees tremble.

His skin began to burn, peeling back in blackened strips. Underneath, his flesh bubbled and melted away, revealing glimpses of the white bone beneath.

He screamed and screamed, his body a crucible of unimaginable pain.

Celestria, Theron, and Sebastian could only watch, horrified. They were frozen in place, unable to speak, unable to move, as their friend was unmade before their very eyes.

Then, as suddenly as it began, the screaming stopped.

The pain on his face was gone, replaced by a calm, empty smile. He was not Marius anymore.

Blood dripped from the raw patches on his skin, but he didn't seem to notice. He stood there, slowly observing his new surroundings.

"Marius?" Celestria said, her voice a trembling whisper. "Are you okay?"

The thing in Marius's body didn't answer. It just stood there, a grotesque statue of flesh and bone.

Celestria started to walk toward him, her hand outstretched. "Marius, it's me..."

"My lady, stop!"

Sebastian's hand shot out, grabbing her arm. "Something's off," the butler hissed, his eyes wide with a deep, primal fear. "The energy... the aura around him. I can feel it. It's growing."

Just then, a retching sound came from beside them. It was Theron. He was bent over, vomiting onto the ground, his body shaking violently.

"Tharon, what is it?" Celestria asked, turning to him.

He looked up, his face pale and slick with sweat. His voice was a cracked, terrified whisper. "Just run. Get away from here. The guy in front of us is not Marius. That's a monster. No, a being more than that... more than I have sensed... combined... in my lifetime."

He was shaking uncontrollably now. "His Aether... it is..."

He couldn't finish. His eyes bulged, and the veins on his forehead pulsed, turning black before they burst. He collapsed to the ground, dead before his body even hit the dirt.

The thing wearing Marius's skin looked at the Headmaster's body and smiled.

"Looks like it was an unfair match," it said, its voice a deep, demonic rumble that was nothing like Marius's. "His ability to sense was his weakness."

It turned its crimson eyes, now glowing with a malevolent light, away from the corpse. "I am not here for any fight with you weaklings. I am here to take what's mine."

Its gaze fell upon Azrael, who was still on the ground, watching everything with a horrified fascination.

The demon started to walk towards him.

"No!" Celestria screamed. She created a massive, silver warhammer in her hands and swung it with all her might, aiming for the back of the demon's head.

Clang!

The warhammer stopped in mid-air, hitting something invisible a few inches from its target. An unseen force then slammed into Celestria, sending her crashing to the ground in a heap of tangled limbs.

"I told you," the demon said, not even looking back. "It's useless. You can't turn the inevitable. The fight was already lost when you entered this forest."

It gestured to the ancient trees around them. "This forest is my home. Or rather, a prison. For a long time. A very long time, more than you can even imagine. And at last, I got something to play with. Something to change my mood."

Celestria pushed herself up, blood trickling from her lip. "Azrael? What do you want from him? He hasn't done anything to you!"

The demon let out a loud laugh. A terrible, grating sound.

"Hahaha! Hasn't done anything to me? You beings are pathetic. Worms like you will never understand the bigger picture." It looked down at Azrael again. "And as for what I want... just as I said. I will play with him."

As it spoke, a black blur shot past it. Sebastian. He had moved with impossible speed, piercing the demon's back straight through the heart with a newly created blade.

The demon didn't even flinch. It reached behind its back, not to pull the sword out, but to punch the man who held it. The blow was a dull, wet thud, but it was too powerful.

Sebastian crumpled to his knees, blood pouring from his mouth.

The demon slowly pulled the sword from its own chest, the gaping wound closing up instantly. It threw the blade to the ground. "Looks like I have to kill all you worms after all."

Its gaze focused on Sebastian. An invisible force lifted the butler from the ground, his hands flying to his own neck as he was choked by nothing.

He was hanging in the air now. Azrael could see the veins in his neck bulging, changing from red to a sickly purple, then to black.

Celestria screamed and attacked again, sending a volley of aether spears at the demon. They were all blocked by the same invisible wall, shattering into silver dust.

Then she too was lifted into the air, her own hands clawing at her throat.

The demon's gaze moved back to Sebastian. Azrael saw tears in the old butler's eyes, a final, silent apology to the family he had served his whole life.

The next moment, an audible snap echoed through the clearing. The force broke Sebastian's head from his body, separating them completely.

His head fell to the ground with a soft thud, his body hanging limp in the air for a moment before dropping beside it.

He was dead.

The demon's crimson gaze now turned to Celestria, who was struggling and choking, her face turning blue.

It smiled.

"Now, your turn."