Since the Katako are half demon the oldest they should be is 30 years old. The Katako age slower than humans but do not live as long as demons. Their life span will reach up to hundred and fifty-eight years max. 30 years of age would be basically a 23 year old in human times, a 20 year old would be a teenager and teenager ages would still just be a teenager.
Katako is not a creature but a Race when writing the application for creature please put Hybrid