In Lost Universe Edit
In the novels, there is no connection between the Slayers world and Lost Universe. Dark Star Dugradigdu is a battleship created by an ancient civilization, whose engine is powered by fear (like the mazoku of Slayers). Since Dark Star had no defense systems, the Lost Ships (including Gorun Nova) were created to protect it. Like Dugradigdu, Gorun Nova's engine also fed on fear. The ship's phase barrier (i.e.: force field) could deflect powerful attacks and could initiate a "void transfer" (teleportation effect).In Lost Universe, Gorun Nova (called "Gore Nova" in the anime), is one of the five Lost Ships created by Dark Star. There are a number of differences between Gorun Nova in the novels and in the anime.
In the anime, Dark Star is a ma-ō who takes the form of a black screeching miasma which powers a gigantic spaceship. His consciousness can also be hosted within a human body - most notably the golden-haired clone of Albert Von Stargazer and Valgaav. Gorun Nova and the other four Lost Ships are subordinates created by Dark Star (also referred to as "System Dark Star"). This technically implies that the Lost Ships are mazoku, and are roughly analogous to the five subordinates created by Ruby Eye Shabranigdu. However, there is nothing in Lost Universe or Slayers canon that confirms or denies this.
In the anime, Gorun Nova also takes the form of a spaceship which feeds on the mental energy of its pilot/captain.
In the Slayers universe, Gorun Nova and the other subordinates of Dark Star appear as the five Weapons of Light. Gorun Nova takes the form of a sword with a blade of light, with sound effects resembling those of a lightsaber from Star Wars. As a result, it became more commonly known as the Sword of Light. Its true name was only known to a few. The Sword's design differs significantly from the design of the other weapons; this may be because, according to Xelloss, the Sword of Light was changed so it would be easier for humans to use.
Like the other Weapons of Light, the Sword of Light channels and amplifies the mental energy, or willpower, of the user, turning it into an attack both on the physical and the astral side. This makes it incredibly useful for fighting mazoku, who do not have physical bodies and therefore can only be hurt from the astral side. It can also be used against foes whose astral bodies are sealed off or missing, and thus are immune to most magics (like Zanaffar in the Slayers novels). The sword is powerful enough to destroy lesser demons and low-ranking mazoku in a single blow if the wielder can manage to hit them. Even middle-ranking mazoku can be seriously wounded or killed by the sword, though for a human, striking one with it can prove exceptionally difficult given how easily these beings can teleport via plane shifting. High-ranking mazoku, however, often display near immunity to the weapon's power, requiring more powerful techniques to kill.
The size and length of the blade appears to correspond with the strength of the user's mental energy, or willpower. Those with strong willpower create a long blade of light, while those with weak or weakened mental energy create smaller, sometimes flickering blades. When not in use, the blade of light disappears, leaving only an empty hilt. An ordinary metal blade can be put in place of the light blade, and thus can be used like an ordinary sword.
Since magic operates on the astral side, the Sword of Light can also be used to channel and amplify spells. For example, Lina Inverse channeled the Giga Slave into the Sword in order to destroy one of the pieces of [[Shabranigdu. The sword can also absorb spells to become stronger for short periods of time.
In Slayers REVOLUTION, Pokota managed to create a replica of the Sword of Light. How he made it and the full extent of its power is unknown, but he did imply that it is a little bit weaker than the original when it flickered out after trying to deflect a Dragon Slave. The hilt of the Sword is also different from design shown in the previous 3 seasons. The replica was destroyed in the battle with Shabranigdu at the end of Slayers EVOLUTION-R.
How Gorun Nova and the other four weapons got to the Slayers world is unknown. Gorun Nova was the only weapon which was inside the mazoku barrier when it was erected at the end of the Kōma War in 0 (?). At some point, either before or after the barrier was erected, the sword came into the possession of the Gabriev family, though they were not aware of its true nature or origins. It is unknown whether she came from the Gabriev family or not, but the weapon was used by the Swordsman of Light during the first destruction of Sairaag around 892 (?) to defeat Zanaffar. As the sword passed from generation to generation, fighting arose over who would inherit it. Eventually, sometime around 1010 (?), Gourry Gabriev stole the Sword and left home to stop the fighting.
In Slayers TRY (approximately 1013 (?)), shortly after the barrier fell, Gorun Nova was reunited with the other four weapons and used to defeat Dark Star. Afterward, Gourry gave the Sword to Sirius, a servant of Night Dragon Vorfeed, who took it back to his world along with the other four weapons. Now Gourry is looking for a weapon to replace the sword.