The Tenth Pillar. (Kimetsu No Yaiba X OC)

Vs Upper Moon one

"Breath of the night, fifth style: Luna Nueva!" Hiiro launched himself at his foe, the demon eyes opened wide, be was blind for just a second more than enough for Hiiro and Tomioka to attack him, but not long enough for them to land a hit on him.

The sword fight continued while Shinobu tried to find an opening, she studied every movement, every little step the Upper Moon took but... there was none, he's a monster.

"Futile." The strongest Upper Moon whispered before parting the attack of the water pillar and kicking the night pillar. "You won't reach my level."

Tomioka and Hiiro retreated and observed the enemy. His stance is perfect, no flaws, no openings. How to beat a monster like that?

'This guy... he's like we are fighting old man Yamamoto.'

He remembered the sparring and training with him, the heat and the strength of the strongest shinigami ever. His strikes were heavy and merciless, he showed no weakness nor restrictions on his flurry of attacks.

'To withstand a stronger force, you have to match it, to fight back. No matter if it's right or wrong, no matter if the enemy surpasses you by far, you have to reach those heights.'

The night pillar parried a slash, Kokushibo showed no mercy, he attacked the demon slayer while he was distracted.

"No time to rest, Kojima Hiiro." A full force kick to the stomach of the young swordsman was enough to break the balance of the sword duel.

"I know, damn it." He took a glimpse to his companions and launched himself to the offensive, again. "Breath of the night, second style: Dusk impact!"

Upper Moon one blocked it with little to none effort. A disgusted face was shown by the elite demon.

"The level of the demon slayers is pathetic!"

As soon as he ended the sentence blood spluttered from his chest. His six eyes opened wide to this. Tomioka Giyuu landed a hit on him.

"Don't underestimate us!" Hiiro screamed as he cut through the demons shoulder leaving him with no option but to retreat.

The pillars regrouped, they landed a couple of hits on him but they knew that the true battle will start from that point.

"I understand. I'm sorry." He sheathed his blade and took a deep breath, a long time have passed since he used this technique so at first he will be a little slow or so he thought but after centuries of practice and mastering his breathing, the word slow had no meaning. "Breath of the moon, first style: Dark Moon-Evening Palace."

A single but fast slash came from him, only with shunpo Hiiro could match the speed of the attack and block it, chaotic crescent shaped blades were originated by the slash.

"Keuk!" The white haori man struggled to keep at bay his foe, he was stronger than him but he could not afford to let him pass, Shinobu was behind him. "Tomioka, now!"

"Breath of the water, eight style: Waterfall Basin!" The sword descended vertically like his name implies, like a waterfall.

The skilled demon swordsman lost his left arm as he took another tactical retreat. A faint but proud smile appeared on the two pillars.

"I've been going easy on you." The demon limb grew again without breaking a sweat, he observed the two young swordsmen, now they were no victims anymore, he recognize them as enemies.

"Breath of the moon, fifth form: Moon Spirit Calamitous Eddy."

Tomioka and Hiiro couldn't see the sword swinging, the could only see the multiple curved slashes coming from the Upper Moon, it was like a rising vortex, sucking the two Hashiras into a deadly trap, multiple cuts and wound were made on Hiiro's body while Tomioka was sent flying into a tree, bloddy and full of wounds.