Why does a caulbearers need to be in possession of their Cauls?
This is mumbo jumbo made up by power hungry followers of Lucifer. After all it is only a piece of dead skin like dead skin left in the bath after washing with no significance at all.
A caulbearer is a reincarnation of an Atlantean who were the natural born leaders of mankind.
When the High Lord left Earth on his travels we Atlanteans were left to integrate with the tribes in different parts of the world, our past life is marked when we re-enter a new body by being born with a caul as a way of showing the tribes that an Atlantean has once again entered into the world to lead them forward.