What is the progression of spirit possession from initial attachment to the aura to become embedded in deeper energy layers?

The progression is one of following the energy. So as the energy swirls around the vortex, they will attempt to ride this energy and to penetrate the outer body energy layer. They need a firmer foothold, so to speak, to maintain their grip on the host, so they need to penetrate the outer layers and then they can impinge on the most central focus point of the chakra where energy is most intense, as the energy comes in as a kind of funnel-shaped vortex and at the point where it reaches the center of the chakra will have the greatest intensity. This is where they wish to be, as the energies come in from both planes of the body so they get a double dose, so to speak, when they are in the center of the action.