The Astrostles Galaxy is one of two major settings of Pseudolonewolf's games, the other one being Alora Fane. It is part of the Figverse. The MARDEK series, Raider, Deliverance, Beast Signer Alpha, SMECOF2005X and The Rise of Yalortism are all set in this location.
The Astrostles Galaxy is simply an addition to the universe of real-life. In Pseudolonewolf's fictional works, divine deities work together to create entire the universe, as described in 'The Crystals', a book found in MARDEK Chapter 3: Keystones. The creation of a planetary system begins with a 'Creator' deity asking permission from the sun-god SOLAK to use a star as a basis of the solar system. If he agrees, the Creator moves on and constructs an Aethereal Crystal to use as a doorway between souls and the heart of a planet. Afterwards, the Creator convinces the 'Elemental Deities' to craft a set of Elemental Crystals, which allow a planet to function, however the Light and Dark crystals are only required if there is to be life there. This process has seemingly been repeated over and over again to create the universe in its entirety. Although he is not the only one, the most common Creator deity is YALORT, who is known to have created both the Astrostles Galaxy and our solar system as reported in the The Holy Book.
The Astrostles Galaxy also has multiple planes of existence. The material realm is the ordinary realm where humans and other races live. The thoughts of those living in the material realm forms the Dreamrealm, the place of minds, thoughts and dreams. All souls permanently remain in the soulrealm however a soul can 'link' to a body and a mind in the material realm to create a person. When that person dies, the link is broken and the soul is taken to a Necropolis, places within the soulrealm where people of the afterlife remain. Unless a certain deity wishes to create a Necropolis of his own, a person simply believing in a place of the afterlife (e.g. heaven or hell) will be able to go there through pure thought. If a person wishes to, he can leave the Necropolis to be reincarnated back to the material realm however his new body and mind will have no memory of his previous life. This process can be repeated as many times as a person wants to.
Another feature of the Astrostles Galaxy is the Elements, which define people, places and abilities. Though everyone's souls are made from aether, a body can take a 'tint' of another element, like fire or light. This contrasts to monsters, which are made from pure energy or Miasma. There are many theories relating to the idea of people having elemental tints, as written in certain bookshelves of MARDEK.