So what what happend to Mizuken( son of Muzan and 17 1/2 years old and a hasira) was when he was born, he was a human, so he got put for adoption. After getting adopted, him and his parents got killed, but since he was the son of Muzan, he regenerated. Then Kagaya found him , and after alot of training, he created Blood Breathing and became a hasira. He killed a bunch of demons, but he died at the age of 17 1/2 in the Sunrise Countdown by getting cut in half ( Horizantally ) with his last words being, Family, are you proud of me.
