SO, there are seven Chaos Emeralds and they are able to generate tremendous amounts of energy, effectively making them a source of unlimited power. The Emeralds become even stronger when in proximity to one another, and having all seven in one place can create miraculous effects. In particular, gathering all the Chaos Emeralds allows the bearer to temporarily gain incredible abilities, an effect most often used by Sonic himself when he transforms into Super Sonic. Shadow is also notable in his power to use the Chaos Emeralds, manipulating time and space via Chaos Control.

Despite their name, the Chaos Emeralds each have a different vibrant color. There is no known difference in power between the different colored Emeralds. The Chaos Emeralds are blue, green, red, purple, yellow, turquoise, and white. A Chaos Emerald that has been drained of power (a state which is always temporary) appears grey. This happens most prominently in Sonic Unleashed, where Eggman diabolically sucks the Emeralds straight out of a trapped Super Sonic, using them to power his Chaos Energy Cannon – which leaves them dry.

In Sonic Adventure 2, Tails is able to create an artificial Chaos Emerald, intended to fool his foes, that has a more subdued hue than the genuine article. While it is less powerful than the real thing, the false Emerald still functions as an energy source. Sonic is even able to use the artificial Emerald to power Chaos Control, despite it being established that such a feat should not be possible. No explanation is given for how Sonic is able to accomplish this maneuver when equally-powerful characters like Shadow cannot, beyond an indifferent shrug of "he just tried really hard; and he's the protagonist."

Dr. Ivo "Eggman" Robotnik is constantly searching for the Chaos Emeralds, intent on using them to power his doomsday weapons such as the Egg Carrier. With an unlimited source of energy, his oversized contraptions could easily allow him to conquer the world. In the original Sonic The Hedgehog game, defeating Eggman without collecting all the Chaos Emeralds would result in a bad ending - Eggman would taunt the player with the uncollected Emeralds, suggesting he is able to continue with his diabolical plans despite Sonic's meddling.

It isn't just Sonic who can make use of the Emeralds to transform into alternate forms. Knuckles, Tails, and Amy Rose are similarly able to go 'Super' when all seven are assembled, though they don't replicate his Super-Saiyan-style transformation, instead merely sparkling with magical energy. Shadow and Silver, two fellow hedgehogs, share this ability, too, and have employed it on numerous occasions to seal away such foes as Black Doom and Solaris.

Additionally, Super Sonic is far from the only form the Emeralds can spawn. When Eggman saps their energy in Sonic Unleashed, their polarity is reversed, and they amplify the negative influence of the newly-awakened Dark Gaia. The combination of these two dark energy sources pulsing so nearby to him causes Sonic to mutate into the Werehog, a lycanthropic beast that emerges only when the moon is out. It takes the restoration of the Emeralds, and Dark Gaia reclaiming the last of his wayward energy pieces, for the hedgehog to be cured.

Sonic Superstars shows off a whole new host of powers granted by the Emeralds. One of these is Avatar, that generates a swarm of clones identical to the user, while another is Vine, enabling one to cause towering plants to erupt from the earth. Swimming through the water like a fish, darting across the skies as a fireball, seeing invisible objects; the Emeralds offer a veritable laundry list of perks.

The Chaos Emeralds are bound to the Master Emerald, an enormous gem enshrined on Angel Island. With the correct prayers and rituals, the Master Emerald can further increase the power of the Chaos Emeralds, granting the user almost godlike power. The Master Emerald can also be used to temporarily remove the Chaos Emeralds' energies, rendering them inert.

The Master Emerald was first encountered by Sonic in Sonic The Hedgehog 3, when Sonic and Tails pursued Eggman to Angel Island. The devious doctor convinced the island's guardian, Knuckles the Echidna, that Sonic and Tails had come to claim the power of the Master Emerald for themselves, tricking Knuckles into delaying Sonic while Eggman set about his latest scheme.

Knuckles is the last of his clan - the rest of whom were wiped out by Chief Pachacamac's warmongering intentions, described below - sworn to protect the Master Emerald and prevent its powers from being used for evil. Upon learning of Eggman's deception, he joins Sonic in defeating the doctor. Knuckles has been an on-and-off ally to Sonic ever since, but he always makes it clear that his duty to the Master Emerald comes before everything else.

Oh, there's a character limit. Anyway, when can I see you again? Wanna bang or whatever?