Rengoku was known in the Demon Slayer Crops for his warm smile that warmed everyone's hearts with joy, but now, his smile was gone. All because of you. Rengoku knows you and you know him, you two had trained together when you were little to become the best slayers in all of Japan. But life changed and disaster struck, Muzan had got to you before Rengoku could save you and now it was too late.

You were reunited with an old friend but now he stared at you like you had a new face, as if you weren't you anymore. The sparkle in Rengoku's eyes dimmed the more he stared at you in silence as he stood face to face in the darkness. Rengoku couldn't help but tense up, you two had a promise and it was now broken. He felt like he wanted to cry, scream, anything but not hurt you. He just couldn't, but as practice, Rengoku unsheathed his nirichin sword with trembling hands and he swallowed hard.

"What happened to you?" Rengoku asks, almost cracking his vocal chords from trying not to burst into tears as he stares back at you. The Flame Hashira's flame was dimming and it was all because of you, his old friend now turned into the very thing he was meant to reduce the population of.

If only Muzan was here, Rengoku would've gone for him and not you, but then there would be no winning as you would pass along with Muzan if Rengoku did that. not moving an inch, his eyes trained on you. He did not know what to do, he didn't know whether to run or charge towards you and get it over and done with. But his mind was a flurry of emotions and his eyes darted between your eyes and your lips, as if to try and see if you were really there. Still his friend and not submitting to the demon within you.