I feel kind of dumb after FINALLY thinking about what UM1 is capable of and said.
1. He's a breath of the moon user. The moon. Night. Where demon shines the most, as a counter to breath of the sun, which is for demon hunters and the strongest breath against demons.
2. He says "Demon hunter... brothers... How nostalgic." It's pretty clear he has some memories of his past considering his awareness of his own bloodline. So would it be surprising if he had a brother that he remembers who also became a demon hunter like him? IE, the sun breath user that interacted with Tanjirou's ancestor? My (as well as many others) theory is that Sun breath user is the brother of UM1. UM1 said he couldn't protect anything in Tanjirou's flashback. Perhaps, he couldn't stop his brother from becoming a demon. This would also make sense since I kinda doubt Muzan would enslave the guy who nearly killed him. The cells reject every fiber of his being.
What I can't make out is the lack of earrings. If he was a sun breath user, where are his earrings? How did Tanjirou's lineage end up with the earrings? How did Tanjirou's father learn of the dance of the fire god when we see that the flashback shows that the Sun breath user was against sharing his story to Tanjirou's ancestor? How exactly did the "sun breath earrings" come to existence in the first place? who created them? So many questions... and not enough chapters
1. He's a breath of the moon user. The moon. Night. Where demon shines the most, as a counter to breath of the sun, which is for demon hunters and the strongest breath against demons.
2. He says "Demon hunter... brothers... How nostalgic." It's pretty clear he has some memories of his past considering his awareness of his own bloodline. So would it be surprising if he had a brother that he remembers who also became a demon hunter like him? IE, the sun breath user that interacted with Tanjirou's ancestor? My (as well as many others) theory is that Sun breath user is the brother of UM1. UM1 said he couldn't protect anything in Tanjirou's flashback. Perhaps, he couldn't stop his brother from becoming a demon. This would also make sense since I kinda doubt Muzan would enslave the guy who nearly killed him. The cells reject every fiber of his being.
What I can't make out is the lack of earrings. If he was a sun breath user, where are his earrings? How did Tanjirou's lineage end up with the earrings? How did Tanjirou's father learn of the dance of the fire god when we see that the flashback shows that the Sun breath user was against sharing his story to Tanjirou's ancestor? How exactly did the "sun breath earrings" come to existence in the first place? who created them? So many questions... and not enough chapters
