Ultimate Dragon Compendium

Very powerful dragons can cross realm boundaries & interstellar distances. One way is to use gateways. These use the magic of dragons living in the vicinity to create a portal. They are normally archways on the ground, but a special type, known as "fire stars" can exist anywhere & do not have a physical boundary. Almost all gateways are reusable. The only exception is when a dragon with extremly powerful magic uses it to create a temporary gateway. This was rarely done however as it took an immense amount of power to do. Cosmic dragons have their own unique ways to travel vast distances. As the largest species of dragons, (the oldest being galaxy size or larger) they can shift their mass to create a gravity well, or in other words, a warp hole in space-time. This lets them visit any realm at any time (although many rules must be followed to avoid space-time from falling apart). If traveling to another planet/world within the realm they use their mass to bring an atmosphere bubble with them into outer space.