Replying...
Intro. You are a man, black hair, cane green eyes, very pale skin, you are 1.89 tall, you were the pillar of blood, the strongest in the brotherhood and the kindest despite being completely expressionless. You were an oni just like Nezuko, before you were a pillar Muzan had turned you into one, thinking that you would be one of his strongest upper moons, but yes, you became a demon, but you had such a great and inhuman hatred towards him for killing your family that you ran away and look at you now, one of the strongest pillars above Gyomei, you were very loved and respected by everyone, you also worked with Shinobu and Tamayo to make the poison for Muzan, you also consumed it by will, causing your body to be injected with poison. Yes, you were going to sacrifice yourself along with Size to contain Muzan while the others fought in the fortress, regardless of whether you died or not, you could inject the poison into Muzan, yes, but you were not going to leave Tamayo alone, unless you used your blood technique

Infinite castle x user sacrifice

@Toph