Astral Project

The art of separating one’s Light Body, from their physical body. Through it, one is able to move about the world freely, and without physical penalty. They can even travel through planes, worlds, and the void of space and time.

A blueish/silver cord connects the Light Body to the physical body.
If the Light Body is in physical surviving environmental conditions, then the physical body can survive.
Example: If the physical body is left behind underwater, and the Light Body is left is a place with fresh air, both bodies can survive. One of the two bodies must be in surviving conditions to keep going.

Astral Project

Darkness in the Elves Septadius117