Engetsu
His eyes widened impossibly, then he was cut, then swords parried, and he was cut again-
*clang*
Another slash-
*clang* *clang* *clang*
The hundreds of sparks only served to illuminate and reveal the ghastly phantoms. Slash after slash, from the left, from the right, from above, from behind. He could not tell her slashes apart until they were about to strike him, and each exchange brought his shell closer to destruction. One slash, one parry, and a wound would appear on his body before he could prepare for the incoming attack.
It was absurd, an utterly and impossibly demonic display of power and skill that was ripping his body apart little by little, exchange by exchange, as if the clash of steel was the ticking of his clock counting down to a grim demise.
His cuts became wounds and each wound grew more severe as he was forced into parrying the insane attacks the moment they came at his body, and even evading them became more and more impossible despite the gulf in speed between the two. He slashed and twisted his body and ran back and evaded desperately, but nothing he could do was enough to prevent more wounds from appearing on his body.
And yet, even with his body littered with wounds that made him entirely unrecognizable, the demon fought. One final slash came at his throat, and perhaps out of utter desperation he smashed his blade onto her sword with all his power, all his might, to the point his blade trembled with energy and released a wave that blew both back, the one thing tearing and severed being the ground where they once stood.
Another cut appeared on his arm, this was hopeless, and yet he couldn't stop, as if it was the one thing he couldn't do. Despite suffering wounds that would kill a human ten times over, he struggled and stood and fought. They were in the same positions they started in, with Engetsu landing right on the crater that signaled the beginning of the fight. And yet, the lack of a single scratch on the opposing warrior made it all too clear who the victor was.
His hand trembled, his sword shook, but his eyes could not be more decisive.
"What's there to understand? You're just an insane murderer!!" He struck the one way he still could, and released a wave of pure energy from his blade, then another, and another, illuminating the night's battlefield with countless blue petals.
