The worlds of "Edolas" and "Earth-land" were parallel worlds. Their maps were basically the same, but the cities were distributed differently, and their specific names were quite different, too.
Perhaps the two parallel worlds were connected in some way, while also having their differences?
Anyway, from what was known so far, people—or cats—with the same appearance and names existed in both worlds, yet had completely different personalities and identities.
But let's leave Earth-land aside for now and talk about Edolas...
In this world, there was an island floating high above the continent of Edolas. There was Extalia, and below it lay the human kingdom of Edolas.
This world had many other magical floating islands, fantastical animals, and even absurd rivers that could flow through the air. All of them were related to the use of magic. Naturally, the overuse of magic had left this world on the brink of magical collapse. That was why they had no choice but to try drawing magic from Earth-land, intending to turn it into this world's source of magic?
In short, that was the truth!
Because magic was so scarce, the humans in the kingdom below Extalia had been forbidden from possessing or using any magic by order of the king. Anyone who possessed magic—or magical items—was considered a criminal.
That was because magic in this world was already extremely scarce, and most of it was stored in the earth. Those great chunks of land were also kept floating in the sky by magic. Whether it was magic or energy, the more you used, the less you had. So, as time passed, the magic in this world would gradually run dry. They had to find a new source of magic, or else this world would eventually face destruction.
And that was the main reason