In this galaxy, there's a small planet. Even if it's small, it's overflowed with magic resource called mana, which makes civilization in it is very advanced and prosperous. As long as there's mana, nothing can't be make with it. Those who specialized in controlling mana is called "Magician". But that advanced civilization has been faced with one of largest problem in that planet. The birth rate is exceeding the mana's flow rate and soon will collapse the balance of the planet. They can't afford to reduce birth rate because in that small planet, even a small disaster could cause their wipe out. That planet is a lone planet. Its galaxy only consist of itself and the Sun. With no other options, they send a representative to consult the "Twins of Void", who manages the dimension.
In this galaxy, there's a small planet. Even if it's small, the people in it is very insightful. Not to mention inside their planet is full of metal resource from the precious metal like Gold, to extremely harmful Uranium that could explode that planet almost instantly. To manage those substance and prevent their planet from exploding, they need a lot of hands. But in that planet full of metal, organic substance is very scarce, not much plant could live upon it. There's a limit for a knowledge without resource. Destruction creep on that planet as people slowly blinded with hunger. That planet is also a lone planet, so refugee is not an option. Faced with their extinction, they decided to send a representative to consult the "Dark Gemini", who manages the dimension.
[Nowhere]
A wide space with nothing inside it. The inhabitants of that place named that space is "Nowhere" as it's the best word to describe that space. Two cracks appears in somewhere in Nowhere. In one of crack, appears a person with delicate robe. While from the other, appears a person with lousy robe. Either ignoring or not realizing other's appearance, they walk toward the only inhabitants in that space.
"Well, well, what a surprising visitor!" the black cat talks.
"What do you needs from Nowhere, mortals?" the white cat talks.
"Our planet is at grave situation, we have nowhere to turning to. Please give us a mercy, Lord of Darkness" a lousy-robed man talked to the black cat.
"Our planet is threatened. With no other options, I come to ask for a solution from Lord of Void" the delicate-robed man talked to the white cat
"My, my, that surely a big problem you have!" the black cat talks.
"Hah! Why do you think I would give you any solutions to ungrateful foolish mortals!" the white cat yells.
"Sssh, Kusu. Calm down. It's our job to maintain the stability of the world." the black cats persuades the white cat, but the white cat only pouts and turn its face. "Hmph!"
The black cat sighs, and turn to their visitors.
"I know your conditions now, or more like from the very beginning of that planets. We're aware of it's unstability and the reason behind it"
"Thanks to someone irresponsibly divide it then waltz out from Nowhere!"
the black cat coughs twice
"As he says, your world is not supposed to be very unstable like that. We'd like to solve this problem quickly but we have to wait for your planet to matures a bit. And once it matures enough, an appearance will come to our space"
"Your appearance"
"Combining two planets from different dimension is not exactly hard, but there's a problem comes from it" the black cat talks
"The souls live on it" the white cat talks.
"I don't think the planet has any complains about combining with it own same but different part of its own" the black cat talks
"But the souls will" the white talks.
"Soul is more delicate, while they're the same, but they can be exactly different. And to combine the souls..."
"...it needs to sacrifice one of existence in other world"
"I'm sure no human willing to do that. So to make it fairs..."
"...An effort will be necessary and the result will be based from it"
Suddenly a glowing light comes to right hand of the lousy-robed man and to left hand of delicate-robed man. One of it shaped like sword, and other shaped like rod.
"If you met your other existence, the mark will glow and you will have to fight against each other." the white cat talks
"The winner will retains its existence and gain the other's memories" the black cat talks.
"You can try to run, but you can never run away from yourself" the white cat talks.
"Oh, and the moment you go back to the your world, the 'new' world, everyone will knows what you heard here. So you don't need to announce it" the black cat talks and smiles.
"So, try your best okay? To exists in the new world" the black cat encourages
"And let the battle begins" the white cat smirks. When his paw taps the 'floor', it's as if the space is falling apart and envelops their visitor.
Pardon my grammar mistakes