The Chaos Emeralds (カオスエメラルド Kaosu Emerarudo?) are seven differently colored, mystical gems with seemly unlimited power in the Sonic the Hedgehog series. They are seven ancient emeralds and mystical relics tied to the Master Emerald, with powerful properties and abilities.
The Chaos Emeralds' background are a mystery to most people and as such almost no one knows where they came from. They have been around for several millennia and predate the Master Emerald which has existed since before recorded time.
The truth about their creation dates from several millennia ago, this knowledge having since long been lost. In those times, seven mystics known as the Elders were proficient users of Chaos energy (which wasn't called that at the time), a mysterious form of energy dwelling from inside the planet. Each of them had not only mastered it to grant them a prolonged lifespan, but also each created and mastered a specific power with it.
These Elders, who each came from different civilisations, left their various homes and banded together in their shared interest in Chaos energy, travelling the world as they researched more of it. At one point they found an orphaned baby hedgehog in the midst of a wrecked village. They took the baby with them, believing all life to be sacred and having sworn to protect it. While at first their goal was to drop the baby off at the first town they encountered, they changed their mind when they discovered his potential in harnessing Chaos energy. Besides, most of them had already taken a liking to him. They then decided to make him their disciple.
Over the next years the Elders raised the boy, who they named Sosigenes, while also instructing him in the ways of harnessing Chaos energy. While the boy did extremely good in basic usage of it, he could only partially perform advanced techniques and failed to invent any of his own. This caused him a lot of stress, often causing him to lash out and asking why he had to do this in the first place. However the Elders knew what they were doing, they knew their meeting wasn't a coincidence and that they had to train him to face the ominous threat that they had felt at one point.
When the threat manisfested itself in the form of the Dark One, an entity that had ventured across the galaxy for eons while consuming every energy source it came across (the Chaos energy coming from the planet caused it to be drawn towards it), the Elders felt that their now teenage disciple wasn't ready for it and went in space to confront the dark entity themselves. While their experience and usage of Chaos energy was vast, it still wasn't enough to defeat the entity. To escape being assimilated, they used a last resort technique to become one with Chaos energy, taking the form of the what would later be called Super Emeralds, and teleported back to the planet.
Reuniting with their disciple, they told him everything; about the Dark one, the danger the planet was in, why they looked like that and that he was their last hope. Sosigenes wasn't convinced about his chances against an entity his masters couldn't defeat. To encourage him, his masters unveiled to him something. While they had each mastered basic usage of Chaos energy, none of them had ever been able to mimic another one's specific ability. The fact that he could already showed that he would surpass them. While still hesitant, Sosigenes went along with them, not really having much of a choice.
Using the short time they had, Sosigenes trained seriously to improve his basic Chaos energy manipulation, including his usage of his masters' powers. With the Dark One nearing the planet, his masters asked Sosigenes to touch each of them and upon doing so shared what power they could share with him. Upon receiving this power, Sosigenes went through a physical change (the would be called Super form). Ready for battle, they headed towards the atmosphere. Facing the Dark One, Sosigenes began his assault. While he was more effective and lasted far longer than his masters, due to combining all their powers, he was still not able to best the entity. As a last resort, his masters fused together with him, giving him a massive power boost along while his fur began to flash in multiple colors (Hyper transformation). With this he continued his assault, seriously affecting the entity and shrugging off it's attacks.
Feeling it's power weakening, Sosigenes prepared to finish it off, but couldn't as the transformation wore off at that moment, separating him from his masters. Fearing it might power up again, the Elders immediately took action and sealed a big part of the entity's power inside themselves. Doing so me ant that they sacrificed their consciousness to suppress that power, a mental battle that would continue for a long time, which also caused their physical form to shrink. Before their consciousness completely disappeared, they all told Sosigenes how proud they were of him and to protect the planet in their stead. Tearfully agreeing, after they completely stopped speaking Sosigenes was overcome with grief. This grief activated his still latent power, briefly flashing again and using this short time to launch a devastating attack against the entity.
Before it could start recovering and knowing he could not destroy it, Sosigenes sealed the most of the entity's power inside the planet before sealing the rest inside himself. After this he crashed down on the planet due to exhaustion. This caused him to overlook a small blob of darkness shooting out in the galaxy (which would later become the Black Comet). Luckily for him, the Emeralds had protected him. After recovering, the power that his masters had shared with him returned to the Emeralds, but he found himself still in the same form. Those who had seen the scene heralded him as a hero, others even called him a god. The battle was engraved on a mural, which also prophesied a second coming of it.
As the years passed, the now immortal Sosigenes passed his time travelling the world with the Emeralds and helping those in need. He also spread the tale of his masters around the globe, so that their sacrifice and dedication would not be forgotten. Sometimes he stayed in one place for a long period of time because he liked it there and settled down for a bit, which is the cause that numerous locations have held the Emeralds at one point.
After several centuries, the power sealed inside the planet bursted out, taking the form of a monster that would later be called Dark Gaia. This caused the planet to be detached in several parts. After subjugating the monster, Sosigenes built the Gaia Temples which could restore the planet with an Emerald's power. Before restoring everything, he created a guardian to do this task if he wasn't present, and called it Light Gaia.
Throughout history, many civilizations have sought to harness the Emeralds' power. While Sosigenes settled there, the ancient civilization on West Side Island used the Emeralds for the advancement of their society and achieved great prosperity. He allowed them because it was in line with his masters' teachings. When West Side Island's prosperity lead to avarice as some people wanted the Emeralds for evil however, a conflict so great sparked that Sosigenes had to intervene personally. Fearing this might happen again, he sealed the Emeralds on the island. Being tired of the world's misuse of them, Sosigenes used the same technique as his masters to become the Master Emerald and balance out the other Emeralds' power.
The rest is history.
After Sonic reached his true potential and learned everything about the Emeralds from his ancestor Sosigenes, he decided they needed to be guarded at all times, but in different places. Their current locations include:
- Blue Emerald: Personally guarded by the blue blur himself, it would later be guarded by his descendants in the Rose family.
- Red Emerald: Guarded by GUN, more specifically by Shadow the Hedgehog.
- Orange Emerald: Given to a gorilla tribe in the rainforest, who were already reputed for their strength.
- Green Emerald: Given to a rabbit ninja clan, known for their efficiency.
The resting places of the other Emeralds are still unknown.
Those that hold the Chaos Emeralds can use their powers for a variety of things, such as initiating a super transformation, powering machines,etc...
- Seemingly infinite power: Being connected with the enourmous supply of Chaos energy from the planet, the Emeralds contain powers way beyond what can be produced on the planet.
- Dual energy source: Due to the negative powers sealed inside them, they can be used for positive as well as negative empowerement.
- Danger instinct: While their respective consciousnesses are not active in the outside world, their strong desire to protect the planet still lives on, causing the Emeralds to appear whenever a world scaled event is taking place.
- Champion relationship: While many people can use their powers, only the one chosen by the Master Emerald can use it to their full extent. This chosen champion, can also summon them to his location when needed. A notable exception to this is Sonic the Hedgehog, who had a special privilege due to being a direct descendant of Sosigenes.
- The yellow Emerald was changed to orange because of preference.