Actions

Work Header

The Deadliest Sin

Summary:

Every demon is assigned a deadly sin upon conception, and Rumi is no different. Following in her father's footsteps, Rumi discovers her struggles with lust and attempts to untangle her demon nature from her human one, with help from the most gorgeous girls and biggest temptations she's ever met along the way.

Notes:

A note about the tags - At times, this fic is going to get heavy. There will be no explicit scenes of sexual assault, but Rumi regularly has to manage nightmares and body flashbacks typical for those dealing with PTSD from similar trauma. Use caution and be kind to yourself when reading. I promise a happy ending is coming eventually.

Also, my version of Rumi is partly inspired by ILovedHerAndSometimesSheLovedMeToo’s characterization in I want to die like a citrus tree (but that's not a milkweed's fate). If you’ve somehow found this fic and not read theirs, you’re really missing out on one of the best in the business!

Chapter 1: Against Their Own Body

Chapter Text

Flee from sexual immorality. All other sins a person commits are outside the body, but whoever sins sexually, sins against their own body. 1 Corinthains 6:18, NIV

Every demon has her shame.

Sometimes it’s evident in the first moments of their existence, baked into a young devil’s very being. Others find it throughout the centuries, reveling in their own errors until the shame settles unshakably deep in their bones.

For Rumi, it started around puberty.

There was The Incident at ten years old when Rumi caught the first glimpses of her shame. Neither she nor Celiene had expected Rumi’s indecency to materialize after a random Tuesday dance class when Rumi pulled on a fresh outfit over her wrist length compression top and found herself staring too long at the way a classmate’s shiny long hair fell over her blossoming body.

Celine thought she had more time before her goddaughter morphed from prepubescent to possessed, time to prepare Rumi for however her demon ancestry took root in her much too human body. But Celiene knew that day as she signed the paperwork to permanently withdraw Rumi from her dance troupe that she had foolishly fallen for Gwi-Ma’s trap when she chose to see Rumi through her own mortal eyes rather than arrange for her inevitable moral failure.

That night, Rumi dressed in her thickest sweater for dinner, despite the sticky late summer air. Her attire didn’t keep Celine from implementing their new weekly ritual of measuring her patterns against Rumi’s log of self-reported transgressions.

“Why did it have to be lust?” Celine muttered as she wrapped the tape measure around Rumi’s bicep. “I could have managed wrath, or sloth, or god forbid; even gluttony.” Rumi flinched as Celiene pulled the instrument tighter than necessary. “But I should have known you’d take after your father.”

Celine jotted down her findings in a plain brown leather bound notebook and handed it to Rumi. “For keeping track of your offenses. Your markings grew ⅛ of an inch today.” She tucked away her sewing kit with a deep sigh. “It’s your responsibility to control yourself the best you can Rumi. I can’t expect perfection, you are part demon after all. But I do require sacrifice.” Celine got up from the table with as much grace and poise as she always did. “Especially given how much I’ve sacrificed for you.”

Rumi got her first period not long after, her body shedding the last of its childlike innocence into the lining of her cotton underwear. She washed the stains out herself and charted her first entry in the journal.

November 7th. Began menstruating. New quarter inch pattern on stomach.

Celine didn’t comment on Rumi’s report during their meeting that next Thursday, but the following day, a box of pads appeared on her bathroom counter as it would the first week of every month for the next eight years.

If not known for her warmth, at least Rumi could count on Celine’s practicality.

Rumi gathered data about her nature painstakingly methodically, noting every time the deep dark pit in her stomach burned when she stepped too near a self imposed boundary. If she remained careful and observant, she could catch it in time, see the looming obstacle and side step it. She began teaching herself to meditate, learning to switch into a state of mindfulness the moment she felt her control slipping.

But sometimes the lust caught her off guard, like when just after her 13th birthday, Rumi found herself transfixed by a young, perky instructor in a dance tutorial as she moved her hips to the music and counted out the beat in time with Rumi’s pounding heart. Later that night as she laid awake in bed, Rumi felt the same throbbing between her legs.

That scar had been a choice, when Rumi felt it begin to snake up her right forearm alongside the dark blue veins on the soft underbelly of her wrist and decided not to stop until her heavy breathing crested against the dark, quiet night.

July 31st. Watched dance tutorial and touched myself masturbated. 1½ inch mark above my right wrist. Biggest pattern growth to date.

Celine became less understanding of Rumi’s situation after that. She yanked Rumi’s hand away from her body and forced her to look at the new markings. “What happens when it crosses your palms Rumi? What will we tell people then?”

Celine hired a personal trainer for Rumi, a no-nonsense middle aged man who forced her to rise with the sun and train her body to bow only to her own will. Rumi understood the unspoken guidance - if she fell into bed every day on the brink of exhaustion, there was no time to struggle against midnight bodily temptations.

But it wasn’t only the bright-hot burn of lust that caused Rumi suffering.

Rumi could understand desire, the way it blossomed in her chest with a tricky promise of hope, hope that her body could be hers to govern and enjoy, that someone, somewhere, someday might be able to see the person peeking through her patterns and help her experience the physicality of being human.

Ultimately, Gwi-Ma feasts on shame. And he must have found Rumi unable to produce an acceptable quota on her own.

It began first in her nightmares. Sticky sheets and creeping hands, reaching up inside of her most delicate areas. Beautiful women morphing into taunting demons, laughing at Rumi’s distress. She awoke sick to her stomach, cackling monsters still ringing in her ears.

Those first days were Celine’s warmest towards Rumi since her toddler years. On the third night of her terrors, Celine came crashing into Rumi’s room, twin swords at the ready, only to find Rumi awake and sobbing, her patterns glowing duly as they returned to their everyday color.

Kkomma Byeol! What’s wrong? Where are they?”

Rumi shrunk away from Celine, limbs still shaking, afraid of how her caretaker would view her lack of self control even while asleep.

Celine softened at Rumi’s display of fear and lowered her weapons. She tenderly sat at the edge of the bed, closer than Rumi could remember her being in years, and stared pensively out the window.

“Your mother saw the creatures in her nightmares too.” They sat in silence while Celine gathered herself, unaccustomed to speaking about Mi-yeong Ryu with Rumi. “She was the fiercest fighter of us all, never allowing a single demon to pass by her arrows.” Celine’s countenance darkened. “Until she met your father.”

Rumi silenced the sobs that still threatened to escape. In all their years together, Celine had only spoken of Rumi’s father in passing, spitting his name out of her mouth like a poison.

“He was charming, the devil. Convinced Mi-yeong that he was different, that his desire for her was pure.” She chuckled humorlessly. “Not all demons inherit their parent’s specific cardinal sin, but he certainly passed his visceral hunger on to you.”

Celine looked at Rumi again, taking in her sweat-soaked pillow and tear stained face. “She warned me of this in her last moments, that no matter your sin, the demons would seek out any leverage possible, violating you while both awake and asleep.”

Rumi felt her herself clench instinctively at the reminder that her body had never belonged to her but rather laid in wait to be overthrown by otherworldly beings. When it became clear that Celine was once again lost to her memories, Rumi spoke up for the first time since waking from the terrors. “What should I do now?”

Rumi hated the pity that washed over Celine’s face. She wasn’t usually the type to feel so openly for others, especially not for Rumi and her sins.

“Keep meditating and tracking your pattern growth. It will be time to seal the Honmoon soon enough.”

Rumi stiffened as she covertly rubbed the pad of her thumb over a small, new mark on her inner thigh that still burned from her dreams. This one felt sharper than the others; Rumi had to keep herself from yanking her hand away in pain.

Celine left Rumi without another word, but kept her bedroom door cracked, a single olive branch connecting the two souls beating in the big empty house.

January 3rd. Night terrors. New mark on left thigh, less than an inch long. Pulses with a piercing burn unlike the others. Still warm to the touch hours after inception.

When Rumi awoke the next day, Celine was already gone, two days worth of dinners sitting on the counter in her absence.

“I will return with good news,” is all the note Celine left for Rumi.

Rumi filled those days with training and reading, just as she would have in Celine’s presence.

Exactly 48 hours after Celiene left, there was a knock on the front door.

“You must be Rumi!” A short bubbly girl with light brown eyes like sweet milk chocolate exclaimed. The girl stepped into the house without invitation, wrapping Rumi’s frame in her deceptively strong arms. “Celine said you were idol pretty, but god, you are just gorgeous!”

Rumi felt her face heat up at the cute stranger’s compliment. Suddenly, another girl about her age, this one nearly a foot taller than the first and wearing the coolest outfit Rumi had ever seen appeared in the doorframe. “Easy tiger, we won’t bite,” she said with a wink.

It took a moment before Rumi realized the tall goddess was talking to her. “Oh!” Rumi stammered, “No, I know. I mean, it’s not like - Who are you again?”

Celine, completely unbothered by the mortifying scene unfolding in front of her, met Rumi with a genuine smile.

“Rumi, these are your fellow demon hunters! You girls are going to seal the Honmoon together once and for all!”

So that’s how Rumi, the half-demon cursed with the deadly sin of lust from her father in the underworld, found herself surrounded by two beautiful teenage girls who were supposed to attach their spirits to hers and help Rumi save not only the whole world but also her very soul.

The gay panic rising like bile in her throat confirmed Rumi’s worst fears that she was deeply and utterly fucked.