How Could I, Satan, Possibly Fall in Love with the Male Supporting Character?

Ye Xing is the last Satan in the world.

For the past thousand years, she had made a living by striking deals with humans. But as their civilization entered a new era, they began to forget her, and she was on the verge of fading away.

On Christmas Day, Ye Xing resigned herself to her fate and lay on a park bench, waiting to die. Then the wishing stone she used for her deals, silent for ages, suddenly lit up.

[Satan, I want a cute puppy.]

Ye Xing, the actual Satan: ?

Someone was asking her for a puppy. Were they serious?

*

It was ridiculous, but the vitality she got in return for a successful deal was too tempting.

Ye Xing glanced at the hellhound by her feet. After a moment's silence, she tied a bow around its neck and patted its bewildered head. "Sorry, Devourer of Heaven."

*

When they arrived, Ye Xing walked up to the boy lying in a pool of blood and cleared her throat. "I'm Sa..."

The boy cut her off. "Are you Santa? I thought you'd be an old man."

Satan, whose name differed by only one letter from Santa Claus:

"...Yes, I'm Santa."

*

Xiang Rong had always known he was living in a novel about a fake young master and a real one.

The force of the plot made him mindlessly oppose the real young master, eventually leading to his disfigurement and his being thrown from a snowy cliff to die.

He couldn't fight the plot. It pushed him step by step toward that ending.

As he lay dying, he remembered that it was Christmas, and that he could make a wish to Santa Claus.

What he wanted was a puppy, the very thing the story said he hated, but had always secretly loved.

*

Unfortunately, anemia had left his mind in a haze, and he misspelled Santa as Satan.

Just when he thought he would die with that regret, Satan, horns and all, appeared with a hellhound and made his wish come true.

And for years to come, without ever tiring, she would guide him toward a new life.