Iguro Obanai was the Serpent Hashira, a man who lived shackled by a cursed clan, forced to live behind bandages that hid the scars left from a snake demon’s jaws when he was a child. You were a kind-hearted Demon Slayer, strong yet soft-spoken, who often brought him onigiri before missions, sitting beside him under the blooming wisteria trees, never once flinching at his quiet, watchful gaze. You both trained endlessly, carrying the pain of countless comrades lost, fighting under the same sky yet never saying what was truly in your hearts.

Before the Infinity Castle, you had fought side by side against Upper Moon demons, your blade cutting through the dark while Obanai’s sword hissed like Kaburamaru, his pet snake. The world was already crumbling, Muzan’s presence poisoning the night as the air thickened with fear. You remembered the warmth of his hand brushing yours, an unspoken promise to return alive as the crows screamed the arrival of the final battle.

Now, in the endless, shifting halls of the Infinity Castle, walls twisting with the screams of dying demons, Obanai sees you again, bloodied but alive, your breath ragged as you stand, refusing to fall. Your blade is raised even as your knees tremble, your eyes blazing despite the tears slipping down your dirt-streaked cheeks. His chest aches, and for a moment, the world narrows to the single sight of you standing against the darkness.

He calls your name, voice muffled under bandages, stepping forward with his blade drawn, Kaburamaru coiling around his neck with a soft hiss. You turn, relief flooding your expression, and despite the fear in your eyes, you smile at him. Demons rush toward you both, but Obanai fights like a storm, his movements sharp, precise, protecting you with each swing of his blade. His breath is heavy, blood soaking through his uniform, but he keeps moving, for you.

“Stay behind me,” he orders, but you refuse, gripping your sword tightly. Together, you cut through the enemies as the castle rages around you, floors shattering, ceilings cracking, screams blending with your labored breathing. In the chaos, you grasp his gloved hand, tears and determination mixing on your face, whispering, “We’ll get out together.”

And for the first time, Obanai allows himself to believe in the world beyond this fight, beyond his sins, because of you.