This is some concept art for a video game / movie / graphic novel idea that my friend had. I've been working with him for the past several months on designing the world of Other Side. To picture Other Side, think of this:
- So, the world has an outward curvature, correct?
- Now imagine: instead of being on the outside of a ball, you are on the inside of a hollow ball. That is Other Side.
Other Side is also kind of an "opposite" world as opposed to the surface world (Outside). While the surface is based on physics and reality, Other Side is based on magic and imagination. However, human dynamics on both sides are much the same, including human nature and war.
Whenever a rainbow is energized by a lightning strike, a temporary portal is created on both sides, allowing passage between Outside and Other Side. Many civilizations (such as Atlantis, El Dorado, and the Mayans) have disappeared inexplicably because they were transported to Other Side.
Perfect rainbows (rainbows created from white light, such as that of the Sun) are capable of transporting people. However, imperfect rainbows (those created from non-white light) created and energized in Other Side are used to preform magic and summon creatures. Summoners are people that can create lightning and thus use magic in this way.

These concept drawings here are drawings of the soldiers and Summoners for two of many civilizations: Atlantis (the surface world civilization that was transported to Other Side) and Atlas (the Atlantis of Other Side that was forced to retreat). There will be many more civilizations here, as well as different creatures.

Yep, I totally like this idea.

Thanks for the replies. I'll post more pictures of the idea, such as the other civilizations and the beasties themselves.

Here's another round of drawings, now of the different creatures you can summon. The first drawing has an explanation of summoning:
1. You shoot a lightning bolt at part of a rainbow you want to create.
2. A rift opens in the ground, and the creature that corresponds to the color you hit emerges.
3. You can either fight the creature and send it back to where it came, or you can try to tame it and revert it to a harmless form.

Different locations have different spectra, allowing different creatures to be summoned more easily. However, all creatures can be summoned in all locations. In the story, the creatures that are readily available correspond to the lifestyle and culture of the people.

I also drew the warriors and Summoners for two more civilizations: the Silf and the Zif.
- The Silf live in a forest of giant, hallucinogenic mushrooms, and are thus always high. They are normally carefree and cool, until an outsider enters. When that happens, the Silf will fiercely drive out the intruder until he is out of the forest or dead, jealously guarding their forest. Summoners wear their prism on the back of a brass headband.
- The Zif were a civlization that were incredibly advanced, with great buildings and a focus on mathematics and geometry. However, several hundred years before the story begins, a barbaric European civilzation stupidly genocided them. Summoners carried their prisms in gyroscopes, so that they could toss their prisms into the air to create giant rainbows for large creatures.