There are a few facts you need to know about Fillead:
1. Fillead and Earth have a unique relationship. If someone dies in Fillead, their soul gets reborn in Earth, and vice versa. Without dying, though, it is fairly difficult to travel between the two.
2. Fillead and Earth are connected to one other world, called Kem. This is the world in which souls are created and destroyed. Only with a combined effort can the Moon and Blood elements access it, that is to say, the leaders of the elements have to decide together whether or not a soul is evil enough to suffer being destroyed.