Yuri didn't react immediately, merely tilting her head slightly in a confused gesture while observing her surroundings.
Dôma's ice spread at a terrifying speed, amplified by his vector power, which slowed the movement of particles while intensifying the cold and the control he exerted over it.
But this inaction was short-lived.
Yuri, currently Upper Moon Two and the second most powerful demon under Muzan's command, didn't take long to strike back.
Dôma soon noticed thin blades of grass taking root and sprouting—an abnormal phenomenon in such an inhospitable environment.
Small emerald-green leaves swayed gently, as if caressed by an invisible breeze, crowned with vibrant purple flowers.
In an instant, a magnificent lawn spread out at Yuri's feet.
The vegetation even attempted to invade the arena, but the farther it extended from the demoness, the more it met fierce resistance from the cold.
"Blood Demon Art: Evening Grass."
Her voice, so low it was almost inaudible, was devoid of any emotion.
This element seemed as lifeless as she was.
"Wow… a wide-range technique? That's really pretty!" Dôma exclaimed, his smile bright and carefree.
Yet, the man was already using Breathing: Total Concentration – Constant, as a prelude to an attack.
"My turn! Oh… I forgot this isn't a Pokémon battle, haha!" he joked, but his next actions were anything but amusing or immature.
All the demons who criticized his attitude fell silent the moment they saw what he was preparing.
With a flick of his fan, Dôma conjured two frozen lotus flowers, each encasing a feminine silhouette.
"Blood Demon Art: Priestess of Winter."
"I see your plants can grow in harsh environments… can I test their limits?" he asked, not even waiting for her response.
The "priestesses" calmly closed their eyes and exhaled a chilling white mist.
The attack, slow in appearance, soon transformed the lawn into a forest of ice sculptures.
In the blink of an eye, the entire arena turned into a biting winter.
Yet, the blades of grass kept growing, freezing and then reviving endlessly.
The duel resembled a tug-of-war between their two arts: Dôma's ice destroyed, Yuri's plants reborn.
Dôma observed his opponent's focused silence.
'Weird… it feels like I'm walking through a swamp.'
Under the combined effect of the dead plants and the artificial winter, the arena's ground had become spongy.
But that alone couldn't explain the loss of vitality Dôma felt as he walked through the grass.
The only explanation was a hidden effect in Yuri's Blood Demon Art.
A bit like Dôma's own crystal ice dust.
This realization made him understand that taking the initiative from the start had been the best move.
If Dôma had let Yuri control the arena, he would've been unable to exert his strength as he was now.
"Winter Breathing – First Form: Kaze no Kizu (The Wound of the Wind)!"
Dôma had developed Winter Breathing himself, striving to match the power of Sun Breathing.
He had tried to replicate Yoriichi's art by drawing on Kokushibô's memories, but he could never harness its full strength.
Dôma concluded that he simply wasn't born to wield Sun Breathing like Yoriichi or Tanjiro.
Why such an assessment?
Unlike Tanjiro, heir to a lineage shaped for the traditional mastery of the Hinokami Kagura, Dôma didn't come from a family that had used Sun Breathing for generations, nor was he destined to kill Muzan like Yoriichi.
He lacked any natural predisposition for the technique.
Theoretically, he could overcome this by analyzing the physical structure of Tanjiro or Tanjuro.
For now, he decided to rely on a crutch until he could perfect his own breathing style.
The result was devastating when combined with his Blood Demon Art.
But… 'it's still incomplete without Kamado Tanjiro or his father.'
He still needed to understand the fundamental differences between Tanjiro and ordinary humans.
"W-What?! Is this the power of Upper Moon Six? Why hasn't he already replaced Gyokko-sama?!" stammered a demon in the background, drenched in cold sweat.
Dôma's blades of ice and wind swept away all the vegetation and struck Yuri head-on.
'One day, I'll be able to kill a thousand demons in a single blow,' he thought with a smile, as his priestesses once again blanketed the arena in a biting blizzard.
Dôma advanced, confident.
For him, the fight was already over at that moment.
"Blood Demon Art: Dance of Autumn Leaves."
Maple leaves surged toward him.
His eyes remained indifferent: a simple flick of his fan, charged with vector power, made the ice crystals react.
Yuri's attack was swept away, dispersing the cloud of dust that concealed it.
The woman appeared, in a pitiful state: one leg missing, her body streaked with deep wounds, covered in frost.
Her incredible Upper Moon regeneration was slowed, almost neutralized by the cold.
The fight was nearing its end.
Kokushibô narrowed his eyes after observing the entire scene.
Unlike their private training sessions, Dôma hadn't revealed many of his cards.
'My intuition tells me he never shows everything…' he thought, tightening his grip on his katana.
"Hmm… I'm disappointed."
Dôma's words made Akaza flinch: a direct insult to Yuri's strength was technically an insult to his own power.
But he wasn't in a position to retort due to the ongoing official event.
Unconsciously, he clenched his fists, regretting Muzan's proposal for the challenge against Yuri.
"I understand that your power lies in absorbing the vitality of your enemies, whether through contact or contamination, to also increase your own strength… but," he paused, looking at the woman on the ground.
"But why base your entire strength on that? It makes you the natural enemy of humans, demon slayers, and warriors like Akaza-sama. However…"
He sighed, disappointed, as if facing a naïve child.
"You didn't anticipate that an opponent could deprive you of the terrain or counter you in your own specialty, did you?"
Dôma shook his head in disappointment.
"Well… I'll put an end to this farce. I'm sure Yuri-sama desires eternal rest."
He approached.
Despite the dire situation, Yuri neither begged nor insulted.
She simply stared at him with an indifferent expression.
'Have I been talking to myself this whole time?'
Dôma shrugged and grabbed her throat.
A dull thud echoed as he slammed her against a wall of ice, then pierced her with both of his fans.
'That was a bit too easy?' he thought as he began to "consume" Yuri, as he had done with Shinobu in the manga.
But suddenly, plants sprouted from his own body!
Dôma destroyed them instantly with his ice and vector power.
'So she realized a frontal assault was pointless and chose to attack from within, through my blood…'
Dôma analyzed the situation and quickly reached a conclusion.
"Blood Demon Art: Scarlet Flower Bloom…"
Yuri's calm voice echoed as red flowers unfurled within Dôma's body, parasitizing and devouring him from the inside.
"Wow, you're devouring my flesh and absorbing my stamina at the same time… you're quite the greedy little thing~"
The spectators squinted, some visibly uncomfortable.
Even Nakime, accustomed to Dôma's insinuations, hadn't expected such bold remarks… especially toward a woman in public.
"Don't worry, Yuri-sama~ A man never backs down from such a vigorous embrace from a woman."
Immediately, Dôma activated Blood Demon Art: Vanity's Paradise.
He dove into Yuri's memories and mental chaos, making her see the memory of someone important in his place.
This tactic was cowardly, and Dôma recalled that a servant of Poseidon had defeated several of Athena's knights in this manner— Aka : Lyumnades Caça.
(Image)
That's why he decided to keep it, despite its high level of cowardice.
"K… Ken-kun…"
For the first time since the fight began, Yuri spoke.
"No, it's me, Dio—cough… Dôma!!"
Yuri's lifeless eyes lit up for a moment with intense love, only to be replaced by fierce hatred after hearing Dôma's words.
But it was too late.
The moment she stopped absorbing his vitality, Dôma neutralized the flowers in his body and froze them.
Yuri lost the initiative and vanished, consumed by Dôma's body in a deadly embrace.
"Phew~ That was a close one, haha… but thankfully, I have experience with energetic women."
Nakime's face twisted into a grimace of disgust. She was not alone: all the demons present showed repulsion at the demon's victory.
Ordinary demons and the Lower Moons preferred Yuri over Doma.
Yet, three of them—Muzan, Kokushibô, and Akaza—remained perplexed.
Why had Yuri been destabilized when she seemed to have Dôma trapped?
Their duel had been a battle of pure will, and, against all odds, Dôma had triumphed.
The trio knew full well that Dôma wasn't someone with exceptional mental strength, beyond his intelligence.
Unfortunately, they knew nothing of Blood Demon Art: Vanity's Paradise.
Meanwhile, the man in question was offering a small prayer.
'Yuri… huh? You lived through so much… I'll survive and keep the promise made to that man.'
Even if he used cowardly tactics, Dôma didn't like lying and intended to live according to Yuri's wishes.
The ice demon had finally understood why Upper Moon Two had received such a strange power from Muzan.
She was a weed, desiring only to live, even at the expense of others.
Yes, she was the embodiment of selfishness, but Dôma saw her only as an unfortunate girl, simply wishing to live a chill life like him.
***
Author's Note:
Well, apparently no one's really interested in an OC's life (honestly, me neither: when I read a fanfic, I mostly care about the canon, lol).
Anyway, I'll still summarize the life Dôma saw in Yuri's memories and explain why she was as destabilized as Seiya facing Lyumnades Caça in Poseidon's Sanctuary.
---
Yuri isn't even her real name: it was given to her by Muzan.
She was born with inhuman traits—her eyes, like those of a ghoul from Tokyo Ghoul.
From birth, everyone saw her as a monster, especially since her mother died giving birth to her.
Later, her father went hunting and never returned.
Yuri never knew if he died or simply fled the discrimination their village heaped upon them.
As a teenager, she became beautiful despite her strange eyes.
Many took her for a demonic manifestation (a superstition, not a real Muzan demon).
The distrust and discrimination turned to violence when the village suffered several months of disastrous weather for agriculture.
Despite it all, Yuri stayed, thanks to one person: Ken-kun~.
He was the source of her exceptional mental strength and allowed her to survive in that hostile village.
Ken brought her food and admired her eyes, which he called "scarlet flowers."
One day, a group of extremists decided to eliminate the "cause" of their problems… while having some fun in the process.
Not knowing Yuri's hiding place, they targeted Ken to get the information needed to find her.
The interaction went wrong: Ken was arrested, condemned, and imprisoned.
Yuri only learned of it when he was already on the scaffold.
Her final memory of Ken was his smile and a single sentence: "You must live."
She decided to flee the village, but a patrol spotted and pursued her.
That's when Muzan found her.
She was already broken (the guards had their fun before Muzan arrived), especially after hearing them boast about torturing Ken because of her.
Transformed by Muzan, she held onto Ken's request—"You must live"—as her core principle but harbored deep hatred for her entire village.
Naturally, the first village she destroyed was her own.
And if you're wondering why Ken never left the village: it was simply a matter of money.
A teenage girl and a young man traveling alone? Impossible to survive.
He was trying to save up, but Yuri's growing beauty drew too much attention… and their fate was sealed.