I Became the Heroine’s Stand-in

Diana, unwilling to lose the chance at having a family, ultimately accepted the absurd proposal.

Her parents showed no warmth, no love—nothing resembling affection. But she convinced herself that it didn’t matter.

They had never lived together before, so of course, it would take time. Surely, in time, they would come to love her just as they had their other daughter.

Clinging to that foolish hope, she endured life at the estate. She endured the falsehood of playing a role that wasn’t hers.

“Lady Mernard, are you all right?”

“M-My head…!”

It happened one afternoon.

While attending her usual lessons, an unexpected headache struck her.

And suddenly—

“Diana, please, protect my daughter’s marriage.”

A plea, spoken as if it were an order, fell at Diana’s feet.

The people in the conversation were none other than Diana and those close to her, yet the scene unfolding before her felt utterly unfamiliar.

“Welcome, Lady Mernard.”

“It is an honor to be received, Your Highness.”

With a trembling voice, Diana looked at the man before her.

He was none other than Ersivan Valencia, the infamous “Devil of the Empire.”

Dozens of fragmented scenes passed before her eyes.

And then—one of them jolted her back to reality.

“Forgive me, my daughter. I pray you will find happiness in the heavens.”

Before she could even scream, Count Mernard pushed her off the cliff.

A cruel, merciless death.

“…What?”

Before she could process what was happening, the vision shifted again.

**”I’m sorry. I know I ruined your life. I know I can never be forgiven.

But… I just wanted to say sorry. And thank you.”**

Lillian Mernard placed a single chrysanthemum before a gravestone.

The gravestone bore the name Diana Mernard.

If Lillian had been alive back then, she might have embraced her.

Diana stared at the name engraved on the cold stone.

Lillian, who had the exact same face as her, stood before it, offering a flower.

“…I’m Diana? And I’m supposed to die at eighteen?”

Then, as if mocking her, a memory surfaced—one from her childhood.

A younger version of herself, grumbling in frustration.

“If I was going to be reborn, why did it have to be as some doomed extra?”

Rebirth. Extra. Diana.

Her once-empty mind began piecing the information together.

And finally, she understood.

“…Damn it.”

“Lady Mernard, such vulgar language does not befit a noblewoman!”

“Damn it, damn it, damn it!”

What little she had remembered confirmed one undeniable fact—Diana Mernard was destined to die young.

At the hands of the very man she had believed to be her father.

The man she had foolishly thought would one day love her.

To Summarize

Diana wasn’t Diana.

She had reincarnated into the world of a novel she had read in her past life: “We Were Never Married, Your Grace.”

The story’s protagonist was her twin sister, Lillian Mernard—the very person whose disappearance had sealed Diana’s tragic fate.

**”Lillian Mernard was always perfect. But perfection came at a price—one that demanded countless sacrifices, no matter the time or place.

She never wished to become perfect, yet her parents thought differently. They were determined to make her the best, suffocating her with their obsession.

She understood. She knew they did it because they loved her.

And she loathed it. The unfortunate reality that there were no villains—only victims—made her feel all the more miserable.

She despised the life of nobility.

As an only daughter, she had endured relentless oppression, suffocating expectations.

So, she made a decision.

‘I’m leaving.’

She faked her own death and ran away.”**

The world always followed its predetermined fate.

And when Diana entered this world, everything unfolded exactly as it had in the novel.

One year before she was to come of age, Lillian faked her death and disappeared, seeking a new life elsewhere.

This happened exactly one year before her contract marriage with Duke Valencia was set to take place.

For Count Mernard, who had been on the verge of securing immense wealth and prestige through the marriage, this was a crisis.

So he sought an alternative.

He turned to the daughter he had hidden away—Diana.

She was identical to Lillian. And since no one knew of her existence, she could take her place without anyone noticing.

And thus, Diana’s present situation came to be.

It was already a tragic and pitiful existence.

But more importantly—

What mattered now was the future.

In the end, Diana followed her father’s orders and secured the engagement with Duke Valencia in her sister’s stead.

But months later, Lillian—whom everyone believed dead—returned.

To conceal his deception, Count Mernard would erase the one person who could expose the truth.

Diana.

Just as she had seen in that vision—he would push her off a cliff without hesitation.

“No. That’s impossible.”

She desperately wanted to deny it.

“Father… wouldn’t kill me like that.”

She had known, from the very first day she entered the Mernard estate, that she would never truly be his daughter.

But… humans are creatures of endless desire.

She had longed for something as simple as a “Did you sleep well?” or a “Stay healthy.”

She had cherished the rare moments when he praised her talents.

She had been ensnared by fleeting warmth, foolishly yearning for love.

Even if she was just a stand-in for now, she had hoped—hoped that one day, she might truly become a part of the Mernard family.

How utterly foolish she had been.

Half a Year After Entering the Count’s Estate

It had been six months since Diana became Lillian Mernard.

And that day…

Was the day she decided.

She would not die.

Diana, summoned privately by the Count, found herself living through a scene she had once read in a book.

“Daughter, I have one last request. Please, protect my daughter’s engagement, which will take place in six months.”

There was a vast, indescribable difference between anticipating something and actually experiencing it.

She had secretly longed for the Count’s love. He was her blood, her father.

And yet, in the end, he was the one who would lead her to ruin.

“How could I possibly refuse my father’s command?”

But by now, it was far too late to defy her fate.

No matter what she did, the Count would force her into his web of deceit.

“I love you, my daughter.”

“…I love you too, Father.”

If she wanted to escape death, Diana had to secure a means of survival before her sister—the true protagonist of the novel—returned.

After agonizing over it for months, she came up with a plan.

She would conceal her true identity from Duke Valencia until the wedding.

Then, once they were officially married, when their relationship as husband and wife was established, she would propose a contract.

If she offered him leverage—something he could use against the Mernard family—surely, he would accept the deal.

And Duke Valencia, the man infamous for seeking revenge against the Count, would find her proposal all too tempting.

“If I do this… if I succeed… I can survive.”

Leaning against the carriage, she gazed at her own reflection in the window.

The same face. A similar frame. Even their voices were nearly identical.

To an outsider, she and Lillian were indistinguishable.

“But… can I truly deceive him?”

Among the Empire’s nobility, there was a long-standing tradition.

Before marriage, engaged couples would cohabit for a period to familiarize themselves with each other, the household staff, and the estate’s layout.

Typically, this period lasted anywhere from a week to a month.

However, given the lack of prior interaction between House Valencia and House Mernard, an exception was made.

Their cohabitation period had been extended to three months.

For three entire months, Diana had to keep her secret hidden from the Duke.

And her soon-to-be husband was no ordinary man.

The infamous Duke of Valencia, whose estate was commonly referred to as “the monster’s lair.”

“But if I try my best, I can pull this off.

No—I must succeed.”

Not for the Count.

But for herself.

Lost in thought, she hadn’t even noticed how much time had passed.

The carriage came to a slow halt.

“We have arrived, my lady.”

“Thank you. The ride was quicker than I expected.”

As soon as she stepped outside, her breath caught in her throat.

Before her stood a magnificent mansion—vast and imposing, yet breathtakingly elegant.

Beyond the long, towering fence, an enormous structure stretched before her.

Contrary to the sinister rumors surrounding it, the Valencia estate gleamed in a pristine, almost ethereal shade of ivory.

It looked more like a priceless work of art than a place of residence.

The limestone bricks, meticulously arranged without the slightest imperfection, formed a seamless architectural masterpiece.

The windows, aligned in perfect symmetry across the second and third floors, shimmered like crystal under the setting sun.

The glass, reflecting hues of crimson and gold, resembled a painting frozen in time.

She had expected something grim and ominous, given the estate’s reputation.

How terribly narrow-minded of me.

“You must be weary from your travels.”

A rich, velvety voice called out from behind her.

She immediately recognized the speaker.

There was only one man in the Empire whose mere voice exuded such effortless nobility.

Forcing herself to remain composed, she turned toward the source of the sound.

And then—

Her breath hitched.

“…Ah.”

A silent exclamation slipped from her lips.

“The devil himself has taken residence in his eyes.”

Everyone who had met Ersivan Valencia had come to the same conclusion.

His eyes were the reason people called House Valencia the monster’s lair.

The deep, blood-red hue of his irises unsettled those around him.

Some whispered that his eyes were cursed, a reflection of the lives he had taken.

Even in the novel, every mention of his eyes was accompanied by grim and ominous descriptions.

But now—

Diana knew.

All of it had been utter nonsense.

“What could possibly be more beautiful than this man’s eyes?”

The deep crimson, like the dying embers of a fire, was unlike anything she had ever seen.

She had no words to describe it.

No human language, no mere arrangement of syllables, could ever do them justice.

“No, my journey was rather pleasant and comfortable.”

“I’m pleased to hear that.”

As Ersivan lowered his gaze, the intensity in his eyes momentarily disappeared.

But even the subtle lift at the corners of his eyes was striking enough to leave an impression.

He then lowered himself, bending at the waist just enough to align their eye level.

Recognizing his silent cue, Diana extended her hand.

The Duke, having already removed his glove, reached for her.

His bare fingers, pale and cool to the touch, wrapped around hers.

“May the gods bless you.”

Words she had heard countless times before.

Yet, when spoken in his voice, they carried an entirely different weight.

His lips pressed against the back of her hand.

And for the briefest moment, her delicate fingers trembled.

A reaction she had failed to suppress.

“There’s no reason for this to feel so strange.”

It wasn’t her first time experiencing such a gesture.

After all, a hand-kiss was nothing more than a mere formality in aristocratic society.

Yet Ersivan’s touch was different.

Unlike anyone else’s.

The warmth from where his lips had grazed spread across her skin, seeping into her bones.

“No. Who wouldn’t tremble?”

As he carefully slipped her glove back on, their eyes met once again.

A quiet, inexplicable flutter stirred within her chest.

And as she held his gaze, her mind corrected its earlier thoughts.

“Who could possibly look at this man—this exquisite, living masterpiece—and not react?”

Her momentary shudder had been inevitable.

Nothing more, nothing less.

Or so she told herself.