So, to recap. Here are Ghaleon's ultimate intentions in each version of the Silver Star story.
TSS: Althena left, and Dyne died as a result of her orders. The world needs an absolute ruler to control it, one that's better than Althena, and Ghaleon will become that ruler.
SSS: Althena became human. The world needs a goddess, and so Ghaleon will return Luna to Althena and place her back as goddess.
SSS Novel: Althena became human. The world needs an absolute ruler. So, Ghaleon will pull all the magic from Lunar in order to power Althena's Star Ship on a journey to Venus, taking only a fraction of Lunar's inhabitants with him.
No really. I can't make this stuff up. Here's the bit that I translated:
Onward to Venus! The launch of the Star Ship Althena is now at hand! KFGhaleon: This is Vane's true form: the ship which navigates the heavens, Althena's Star Ship. Our ancestors once came from the Blue Star to this world, aboard this ship. And after much effort, we inherited this world, suitable for life. But, this world is once again in crisis. There is no longer any time. We must once again use this ship to embark on a journey to a new world. Our destination: the morning star, Hesperos.
Nash: Oh, I see! But even then, that doesn't make what he's trying to do right...
Kyle: Shut up so we can listen to the rest!
Laike: Ghaleon... you couldn't possibly fit every single person on that ship...
[Editor's Note: the morning star is "yoake no myoujou", which refers to the planet Venus; moreover, Hesperos was the Greek name for Venus as it appeared in the evening.]
Ghaleon: Through the cooperation of the Goddess Althena and the Four Dragons, I have resurrected Vane's true form. But it cannot journey to the stars as it is right now. It would require immense magic power. Henceforth, I will gather all the magic in this world, to launch the Star Ship. In that time, I shall choose who among you shall be able to continue your existence.
Even though many who were gathered did not understand what he was saying, they knew that it was a bad omen. Alex, however, knew the full extent of what Ghaleon meant to do: he would draw all magic from Lunar, turning the entire world into the same condition as the Frontier, while he and others he chose to survive with him would be able to escape on the ship he had pulled from Vane.
Ghaleon: The world will return to how it originally was. But, for humans--no, for all races--to survive, some sacrifices are inevitable. That is his, and Althena's, conclusion... The countdown until the launch of the Star Ship has already begun. Anyone who dares oppose me should act now.