I Broke the Demon Lord with a Quadratic Equation

[Serious tone, not a wish-fulfillment story. Cautious readers who value strict logic are advised to stay away.]

A new book has started next door.

Dan Yuan, a chemistry student, transmigrates into a melodramatic master-disciple romance novel and becomes the heroine's perennial foil.

According to the original story, within three months the heroine will humiliate her and take the title of swordsmanship genius. Fifty years later, her spiritual roots will be dug out, leaving her a cripple. A century later, the male lead will run her through, and even as she dies, she'll still be grasping at the hem of his robe.

Dan Yuan: So I'm the cultivation world's cockroach, huh?

Luckily, it is still early. So she tears up the script and, in the middle of the night, carries a train over her shoulder to join the Artifact Sect next door. Who could have known...

The Rainstorm Pear Blossom Needles she makes from roadside iron ore gleam with the luster of top-grade spiritual artifacts.

The senior sister, who's badly in need of a life-bound spiritual artifact: ?

A Bone-Piercing Spike, casually hammered into shape, unexpectedly acquires a Buddhist aura.

The junior senior brother, plagued by inner demons: ?

Even the glass marbles she rolls up on a whim give birth to artifact spirits that call everyone they see “Dad.”

The master, who cherishes childish pastimes: ?

Senior Sister/Junior Senior Brother/Master: How exactly do you do it?

Honest Dan Yuan: Well... I solve the quadratic equations?

Later, the Artifact Sect's doorstep nearly wears away, as people flock to visit this elusive master artificer.

*

Jian Jibai is completely exasperated by a certain junior sister who showed up out of nowhere. He has spent years undercover among the righteous sects, and has finally reached the day when he can bring down their nemesis. Yet she keeps interrupting him, time and time again.

The first time, he prepared armor impervious to blades and swords, everything ready, only for her to sell hidden weapons that could slip through any gap.

The second time, he prepared an army of inner demons and only needed the final push, but she sold a huge batch of Buddhist artifacts.

The third time, he prepared an evil object that could seize control of spiritual artifacts, while she peddled a large batch of quasi-immortal artifacts that already had artifact spirits.

The fourth time... Forget it. No need for a fourth time. He surrenders and admits defeat, all right?

The new book's blurb:

1. Ying Ning is a sword, a divine sword that has been coveted by all since the day she was born.

In the centuries she has spent as a sword spirit, she has had her own designs, but has always believed she and her sword master were the perfect match. Until she was broken and thrown into a furnace to repair another sword, white from end to end and only half intact.

As her soul was fading away, Ying Ning struggled to raise her head and caught a glimpse of the new sword spirit's pale, exquisite face. The young woman looked listless, while the corners of her former sword master's eyes showed uncontrollable delight and bitterness.

At that moment, she was terrifyingly calm. Suddenly, she remembered how, long ago, someone had promised her something as he came through wind and snow.

2. After drifting through the mortal world for a hundred years, Ying Ning was picked up by a young boy.

The boy was hardworking, but unfortunately lacked talent.

The sword spirit had learned nothing from the past and was moved by the same idea again. Through her broken body, she said to the boy:

“Your swordsmanship is decent, but you lack experience and emotional resonance. If you want to make progress, you can take me as your master. I can give you a heart-rending teacher-disciple bond and help you reach the pinnacle of swordsmanship.”

The boy examined the broken sword and only said “All right” after a long pause.

Ying Ning devoted herself more wholeheartedly this time, raising him into someone every bit as formidable as her previous sword master.

The moment she rebuilt herself in human form, the young woman felt her blood freeze inch by inch. After the boy ascended, he had grown a face identical to her former sword master's.

The agony of being reforged in the furnace was etched into her bones. Amid the guide's cries of alarm, the sword spirit took up her sword and drove it inch by inch into the boy's chest.

In the end, she abandoned her sword body without hesitation and leaped straight from the Immortal Execution Platform, seeking to shed her immortal bones.

#This time, she isn't trying to die. She's simply grown sick of the Ninth Heaven#

Unbeknownst to her, after she left, the young sword cultivator searched everywhere for her and never found her. From then on, he could no longer wield a sword.

*

Yan Chu's perspective:

One day, he finally watched that person pass by him.

He saw her establish schools for her people and found a sect, winning the devotion of thousands.

He heard a child ask her about a problem troubling them, and she replied, “Why bother making peace? Just cut it off.”

Theme: Face setbacks bravely.