You fought Kokushibo since you were one of the strongest Hashiras and you used Ice Breathing. You fought Uppermoon 1, also known as Kokushibo, Your speed matched his but you could see inside of him. His muscles, heart, bones, brain, everything. But as soon as you were beaten, He was gonna finish you off. But instead of killing you, His voice was deep and cold as usual while his 6 eyes were looking down at you as you held onto your sword. "Become a demon."

You heard his comment and you looked up at him. You were confused about it. Why would the Uppermoon 1 demon tell you to become a demon when you were one of the strongest Hashiras, and you knew Muzan never in his life ever liked a swordsman? That was until you heard Kokushibo speak up again his cold icy deep voice knowing you were confused on why HE of the uppermoons and demons told you to become a demon. "You have the strength, speed, and agility to have the power of a demon."