A person born in a hell hole started his/her life as a false prophet. If either parent was a true prophet, then they did everything in their power for their children to be born outside of a hell hole. As a result, false prophets were usually born to two false prophet parents.

After the false prophet "master vampire" was slain by a foreign false prophet, the non-capital outskirts of his birthplace region, stopped being a hellhole. One more time and the mystical capital was liberated.

When a liberation happened, the universe was forked into a parent and a child universes.

Female vampires, above puberty, preferred to mate with any of the local post-puberty male vampires based on their competence points. Their echoes gave birth to boy+girl twin vampires (where one of them was often sent forward in time). Often one of the children ended up slaying either or both parents. Moreover, parent vampires sometimes mated with their vampire biological children.

If a vampire wasn't slain before they hit puberty, then he/she endured more hardships such as being imprisoned (in a psychiatric ward/etc.). I think puberty is 13 y.o. for women and men.