"It all starts with this...A jewel containing the ultimate power...!!!"
The ITWverse is a strange and often horribly disorganized mishmash of people, places, powers, and origins, but one overly prevailant force in play is the seven Chaos Emeralds. Unlike the original Sonic universe, ITW handles the emeralds in a much more hands-on manner. In addition to being used to power up machines, cannons, and hedgehogs, most characters in ITW are able to harness at least a little bit of an emerald's power, though most abilities are only effective in a combat situation.
Further seperating the ITW physics from the source material, the seven emeralds themselves are elementally aligned, mostly by color:
- Ruby -- Fire and heat, this gem controls all things high temperature. Certain applications of the ruby can even generate magma if used properly.
- Sapphire -- Ice and cold, the darker of the two blue gemstones governs lower temperatures. The sapphire cannot create water, but any within range can be frozen instantly.
- Aquamarine -- Water is ruled by the lighter blue. It doesn't just create water, it can control the ebb and flow of it at will.
- Topaz -- Lightning is the force dominated by this gem. For that reason, most machines would find the topaz to be the most prefered of all seven to be a power source.
- Emerald -- Earth and ground is under the jurisdiction of the namesake gemstone. With the right user, the emerald could create entire mountains or valleys.
- Diamond -- Light energy is what this jewel commands. An effective wielder can create anything from a focused beam to a blinding flare. It's important to note that just because it's light doesn't make it "holy". It's simply the element alignment.
- Amethyst -- Shadow/Darkness on the other end of the spectrum falls under the category of the final gem. Anything from inducing a blinding field of pitch black to firing waves of dark energy are within reason for this one. Again, it's important to note that darkness does not necessarily mean "evil" by any means. Like any power, it depends entirely on the will of the user.
- Chaos -- The energy type most Sonic fans would be familiar with, chaos element is the baseline alignment that all seven emeralds have, regardless of anything else. This is the normal element type behind such things as Chaos Control or Super Sonic. Since all emerald powers share the Chaos element, an attack from an emerald is naturally more powerful and more capable of damaging an opponent than a normal attack of whatever element is used, making the emeralds much more effective against opponents who would otherwise be impossible to defeat with a certain element.
As stated, most people can use the power of at least one emerald, though which one depends entirely on the user in question. Some people can use the emerald, some the ruby, etc. What also sets people apart from one another is how much of an emerald's power they can tap into. A prime example of the variety of this would be Sonic, Shadow, and Dr. Robotnik. Sonic has proven a complete lack of ability to use even the more basic abilities one could utilize with the emeralds, but is capable of using the high-level ability of Chaos Control, as well as using all of the emeralds together to go Super Sonic. Shadow is a bit closer to the middle of things, able to inherently use chaos energy techniques and power up said techniques with the emeralds, as well as go Super himself. Dr. Robotnik, on the far end of things, cannot access any emerald powers at all, and can only rely on machines to utilize their power instead. It all depends on the person with the gem in hand, and though it's been noted that people who are able to understand and attune themselves to the flow of power in the emeralds are usually more capable of using them, there always exists such a thing as having talent for it.
Due to their value and overwhelming power when used in battle, it's no surprise that the Chaos Emeralds are one of the more highly-prized items in ITW for a group to take possession of.
One could also argue that, for that very same reason, the emeralds themselves are what brought about The Cataclysm in the first place.
Though no one has ever done it, it IS theoretically possible for someone other than the usual Sonic characters to collect all seven emeralds and activate a Super form. The chances of it happening are admittedly slim, though. Who'd be crazy enough to actually do something like that?