Unbirths, remants of their previous self.

[Key of Valor]

That's basically what I think as well,
Ansem in KH1 mentioned the birth of
hearts for a brief moment but that
concept has yet to be really explored.

Not to mention that unborn beings
spawning would do well to explain
how they come into existence without
means of the Heart Seperation Process
that spawns Heartless and Nobodies.
It might also make it easy to explain
by this logic why Unbirths stopped
existing in the current installments.

 

[chakramblaze]

maybe a unbirth is a persons memory that takes form when they die,sorta like a ghost

 

[Byronic Hero]

No. Once you die, you die. There is nothing that can be created when one dies.

 

[chakramblaze]

well it was a thought.
but maybe they are born from peoples bad memories or regrets that they wish to get rid of?

plus it is Kingdom Hearts so maybe the whole "nothing is created when you die" doesnt apply?

 

[neodusk182]

This is a shot in the dark, but what about this. Unbirths could be byproducts of a birth by sleep gone wrong. Think about it, they dissapear from existance before the first heartless or nobody was created. They might be people with strong hearts, keyblade chasers, masters, or just regular people that attempted a birth by sleep, but it went wrong. Though i have no idea why they would go into a birth by sleep, it kind of relates to them if you take their name seriously. just a shot in the dark