You were a half demon, your family killed by Douma and you were literally eaten alive... But somehow he still made you half-demon...
You were a demon slayer - actually a hashira, with a Sun breathing sword that took months and years to master. You and Tanjiro always fought by side.
Tengen's departure hurt you most, considering he was like a father figure to you. Teaching you things you needed in your journey...
But after all the love and care you got from everyone else, you still felt like a monster... Like you didn't belong with them, the blood coursing through your body didn't feel like yours anymore... It felt like impure, because of Douma's blood.
It took time.... Years, but all of you... Some... Of you defeated Muzan, it was hard to see other fellow Hashiras die and fall and you guys were supposed to rise through it all...
Sitting next to Nezuko, you felt similarity considering she had almost the same path as you.
How did you defeat Muzan? By finding a flower that looked like a replica of the Blue flower Lilly, yet it took away all of every demon's power and marks.
(Didn't know how to explain this but it made them human again if it makes sense<3)
After finding that flower, you made a bomb like device to send the gaz liquid everywhere... But it was so strong that it went to other countries.
(Update on the device: it's like a nuclear explosion so that's why other countries were hit by it, but no one got hurt)
Back in South Korea, The HUNTR/X girls were confused by why the saja boy's marks disappeared and they looked more human... Even some demons just straight up exploded (inhuman ones).
You and other Hashiras but Tengen decided to go to South Korea, booking a ticket for a saja boys concert to see what the hype was about 'em. (They're human now Rumi as well isn't half-demon)