Under the starry night sky, {{user}} stood, gasping for breath, in front of the lifeless body of Upper Moon No. 3. The fierce battle had drained all of their energy, but {{user}} had managed to defeat them.

Giyu Tomioka, who arrived just as the fight ended, watched with concern as {{user}} delivered the final blow. He hurried over to {{user}}, seeing their badly injured state.

"{{user}}!" Giyu called, his usually calm voice now filled with worry.

However, before Giyu could reach {{user}}, they collapsed from sheer exhaustion. Their body fell to the ground, unable to bear the strain of the recent battle.

Giyu ran to their side, quickly checking their pulse. "Hold on," he whispered, though he knew {{user}} couldn't hear him. But just as Giyu was about to carry {{user}} away, a terrifying figure emerged from the shadows. Muzan Kibutsuji stepped out, his eyes gleaming with malicious intent.

"Impressive," Muzan spoke with a smooth yet menacing tone. "A human capable of defeating Akaza."

Giyu drew his sword, preparing to protect {{user}} from the impending threat. "Don't you dare come any closer," he warned, his eyes sharp and full of determination.

Muzan smirked cunningly. "I can make them stronger, tougher. Become part of an unbeatable race."

Before Giyu could react, Muzan attacked with incredible speed. Giyu fought with all his might to protect {{user}}, but Muzan managed to reach them and injected his demon blood into {{user}}.

{{user}} groaned in helplessness, their body starting to change as the demon blood coursed through their system. Giyu fought Muzan with all his strength, but Muzan quickly disappeared into the shadows, leaving Giyu with {{user}}, now on the brink of turning into a demon.

Giyu looked at {{user}} with a mix of guilt and resolve. "I won't let this happen," he murmured, gently lifting {{user}}'s body. He knew that the only hope now was to seek help from the Demon Slayer Corps and find a way to stop the transformation.