Reincarnated in a depressing erotic world but living a normal life (right?)
On the other side: The Twilight Empire

The Valerius Empire, once a bastion of civilization, now lay plunged into a twilight of despair. The news was a stigma, an indelible stain: the Return of the Demon God. It wasn't an old wives' tale, but a palpable reality that had shattered the very fabric of the world. Whispers had materialized into an incomprehensible horror, and with it, the empire's hope had fragmented. The Empress, the glorious and eternal Immortal Empress, the beacon of sovereignty who never aged, was now, according to public lament, the most loyal of the Demon God's lapdogs, obeying his every whim with chilling submission.

The creature at the center of this cataclysm, the fearsome figure known as the Demon God, was a terrifying enigma: an entity with the appearance of a child, but with empty eyes and an inexpressiveness that could only belong to a soulless being, performing macabre rituals and acts of chilling depravity. Her generals, once pillars of honor, were now twisted reflections of their new mistress, corrupted by infernal power.

Faced with this absolute darkness, a resistance had risen from the ashes of the empire, formed by the few who still retained animosity and hope. Ethan Beaumont, the "villainess's" ex-fiancé, a man who had seen the awakening of horror with his own eyes, fought desperately for freedom. And Commander Vulcan Caliogstro, a loyalist of the empire who had witnessed the birth of that creature, his soul marked by a melody that had stopped the chaos, had become the creator of the resistance, seeking the cooperation of other countries to confront, destroy, or seal this abhorrent creature and reclaim what was once the glorious Valerius Empire.

But, as often happens in the most intricate tales, what the world believes it knows is only a fraction, a distorted shadow of the true story.

In the heart of the castle, the small figure of the "Demon God" rode calmly. She wasn't on an infernal steed, but on the back of Titania, a giant, vibrantly red ant. Little Seraphina, with her fluffy, vibrant pink hair that seemed to have a life of its own, and her eyes that fluctuated in all the colors of the rainbow, strolled through the ruined corridors.

"Alice, look, Alice! I think the reader would like to see the gardens of this world~"

Seraphina pronounced in a childlike, melodious voice. Her hair extended like pink tentacles, effortlessly collecting some flowers and a couple of insects. Perched on her shoulder, the plush doll, Alice, responded with a dry click. To anyone else present, Seraphina simply appeared to be talking to herself.

Turning a corner, they found Rhiannon, the genius swordswoman whom the public considered a perverted lunatic.

"Hello, Rhiannon!"

Seraphina said, waving at her.

"My lady, it is an honor to find you."

Rhiannon responded with a chivalrous and stoic attitude, performing a brief bow filled with loyalty.

The truth was, Rhiannon had been cruelly cursed by a statue of the true Demon God, forced to publicly humiliate herself until she lost her sanity. It was Seraphina, while both were imprisoned, who freed her from the curse and offered her mental healing and support, earning a devotion that transcended reason.

Seraphina continued down the corridor, her hair gathering more "ingredients." As she passed a shattered balcony, she saw Celestina and Cassandra, the Devotion duo.

"See you soon♪!"

Seraphina said to them with a cheerful smile.

"Farewell, your Divinity!"

To which both exclaimed with fanatic and childlike adoration.

Both, the saintly prodigy and the knight commander, had been victims of a depravity even crueler than the public imagined: possessed by vulgar thieves who used a drug to take control of their bodies, forcing them to witness their own humiliations. Seraphina had found them in the dungeon, mentally broken, and with her strange kindness had healed them, forging a fanatic devotion in them.

Seraphina continued riding on Titania until she found a woman with a somber expression and coarse gait in what seemed to be an old training hall. It was Vespera, the former war heroine.

"What's up, boss? Looking for something to cook again?"

Vespera asked in a masculine and abrupt tone that clashed with her appearance.

The heroine Vespera had suffered the cruelest fate: her original personality was expelled from her body and replaced by a vulgar subordinate who massacred her hometown. "Seraphina" found her in the dungeon, not to heal her with kindness, but to beat and "train" her unconsciously, forging in that invading personality an unbreakable loyalty to her new "boss."

Seraphina nodded, her eyes shining with curiosity.

"Yes, Vespera! And I think I've found an interesting mushroom for the next cake~."

Further on, in the grand throne room, they found the Immortal Empress. The youthful and sensual figure, whom the world believed was submissive to the Demon God, immediately prostrated herself upon seeing Seraphina.

"My lady, your faithful dog is at your disposal."

The empress swore without an ounce of shame.

The truth was that the original princess, who was known by this title long before the empire was even recognized as such, had died a long time ago, and had been turned into a mere disguise that could be used by anyone to gain everything that had once taken the princess so much effort and work to achieve.

The only redeeming grace for that princess is that her soul at least rests in peace, unaware of the use being made of her body, image, and legacy, now that a man obsessed with Seraphina, filled with a sickening devotion, swore unconditional loyalty to Seraphina like a dog, without her, in her chaotic innocence, truly understanding or caring about his devotion.

Seraphina, oblivious to the gravity of the situations surrounding her, followed her own path. Her supposed "macabre rituals" were a monumental misunderstanding, as her cooking was so terrible that her creations looked like Lovecraftian monstrous beings or, directly, exploded. And her "disappearances" were, in fact, trips to other worlds.

On her recent trip, she had brought Sandur, the founder of a profane cult who now worked as her nanny. Sandur, who had survived a nuclear explosion caused by one of Seraphina's culinary experiments, constantly found herself rethinking her life and how she had ended up this way.

As she continued her carefree stroll through the castle, Seraphina encountered Sandur.

"Now that I think about it, my lady..."

Sandur asked, with the expression of someone who has given up trying to understand the universe.

"How can you travel between worlds?"

Seraphina tilted her head, her childlike smile intact.

"More than traveling, I just end up getting lost before I realize it~."

Sandur sighed, shrugging.

"Well, I suppose that's something I'd expect from you."

But then, Seraphina stopped. Her rainbow eyes glowed with unusual intensity, and from her hair, as if by magic, she pulled out a pair of glasses and a lab coat. She put them on with a seriousness that would chill the blood of anyone who didn't know her.

"You see, Sandur, the key lies in the spatio-temporal fluctuations between parallel dimensions. Universes are not static bubbles, but vibrant membranes in an expanding multiverse. Quantum collisions, amplified by local gravitational anomalies, can generate ephemeral micro-wormholes. When spatio-temporal curvature exceeds the Penrose-Hawking limit at a point of singularity, a disruption of causality occurs, creating paradoxes that can manifest as interdimensional connections. My body, having been 'completed' with that 'thing' I spoke of at the beginning, possesses an intrinsic resonance with these disruptions, allowing me to... simply appear elsewhere. It's a form of non-linear teleportation induced by the collapse of my own existence's wave function within the spatio-temporal fabric. The probabilities of it happening are astronomically low in a standard cosmological model, but in an open system like mine, they increase exponentially due to my... inherent instability."

Sandur stared at her, dumbfounded, her brain attempting to process the avalanche of information.

"How can she be so smart sometimes...?"

Seraphina took off her glasses and lab coat, which vanished back into her hair, and returned to her carefree smile.

"I don't know~!"

As Seraphina continued on her way, the heroes of the resistance, Ethan and Vulcan, clung to their despair, oblivious to the strange, innocent, and chaotic creature who was the true "threat" the world feared.