Master Emerald

The Master Emerald (マスターエメラルド) is an object that appears in the Sonic the Hedgehog series. It is a massive green emerald and a mystical relic of immeasurable power from the forgotten past. Created by the gods, the Master Emerald acts as a counter to the Chaos Emeralds. The one who controls the Master Emerald can nullify and control the Chaos Emeralds, making the Master Emerald a very valuable gem.

The Master Emerald rests on Angel Island where its power keeps the island afloat in the sky; without it, the island will fall down. Over the last four millennia, the Master Emerald has been guarded by the surviving echidnas of the Knuckles Clan who has kept the gem safe from those seeking it for their own gain. In the present day, its current guardian is Knuckles the Echidna.

Background
The Master Emerald has existed since before recorded time, so the details of its origin is shrouded in mystery. It is said that it was created by the gods as a balance against the power of the Chaos Emeralds after they saw people use them for evil, and equipped the gem with the ability to nullify and control the Chaos Emeralds should anybody attempt to misuse them. An ancient mantra associated with the Emeralds eventually arose, explaining their connection and abilities.

Over four thousand years ago, the Master Emerald and the Chaos Emeralds resided in the Altar of the Emeralds, a shrine in the outskirts of the Mystic Ruins where a colony of Chao lived peacefully. The shrine was protected by a sacred barrier, preventing anyone from taking the Emeralds. Eventually, a residential Chao encountered the Master Emerald and got mutated into the mystical water beast Chaos, who became the guardian of the shrine's inhabitants and Emeralds. As the ancient Knuckles Clan arose, the members would revere the Master Emerald as a sacred object. It was around four thousand years ago that Tikal, the daughter of chief Pachacamac of the Knuckles Clan and a friend to the Chao and Chaos, was allowed into the shrine. There, she saw the Master Emerald and understood its role from her clan's mantra.

As the Knuckles Clan faced extermination at the hands of the Nocturnus Clan, Pachacamac and his followers launched a raid on the alter to steal the Emeralds and gain undisputed power. Tikal stood between them however, begging her people to leave the creatures, and the Emerald, in peace. However, her pleas fell on deaf ears, and the men trampled over Tikal and the Chao alike in the process, prompting Chaos to appear and wipe out most of the clan in a fit of rage as Perfect Chaos. The creature out of control and poised to destroy the planet, Tikal prayed to the Master Emerald to stop Chaos. In response, the gem sealed both Chaos and Tikal inside itself. In the process, it created an energy surge that ripped off a large part of land and it into the sky where it would float with the remaining echidnas, creating Angel Island. With the Master Emerald keeping the island airborne, the surviving members of the Knuckles Clan would devote themselves to protecting the prized gem in hopes of preventing a tragedy like the Chaos incident from occurring again.

Throughout history, many people tried to steal the Master Emerald, and each time, they were thwarted. Over the centuries, the few surviving members of Knuckles Clan became even fewer until only Knuckles the Echidna remained. Brought into the world to guard the Master Emerald, Knuckles assumed this role, knowing from innate knowledge that this was his purpose, and spent his life in solidarity.

Powers and traits
The Master Emerald is renowned as the most powerful relic on Earth, surpassing even that of the Chaos Emeralds which are said to bestow ultimate power. It holds unbound and infinite power in the form of extremely potent and raw chaos energy which can harnessed to power machinery, enable Chaos Powers and initiate a super transformation. Like the Chaos Emeralds, its power can also be harnessed to perform certain reality-warping feats, such as transporting Onyx Island through time and restoring a planet shattered with Chaos Control.

As its primary function, the Master Emerald contains special powers that lets it nullify and control the Chaos Emeralds' energies. This grants it the ability to either completely shut down the Chaos Emeralds' energies or potentially amplify their power. However, it is only those from the Knuckles Clan, such as Knuckles and Tikal, who can harness the full potential of the Master Emerald and communicate with it. To unlock its power, these guardians must on most occasions recite Tikal's Prayer.

Like the Chaos Emeralds, the Master Emerald seems to possess some sort of sentience. It appeared on its own in an attempt to stop a rampaging Emerl and it can create three-dimensional holographic images within itself to communicate. In addition, if the Master Emerald is shattered into several pieces, it can repair itself if its shards are brought back together. However, shattering the Master Emerald seems to give the shards an explosive trajectory, causing them to fly a great distance which makes the task of gathering them rather painstaking.

The Master Emerald is a unique transcendental object that exists simultaneously in all time lines across the time-space continuum. That means should the Master Emerald disappear in one time frame, it would cause a chain reaction that would make it vanish from all existing time frames.

Sonic the Hedgehog 3 & Knuckles
In Sonic the Hedgehog 3 and its add-on continuation Sonic & Knuckles, the Master Emerald came under threat when the Death Egg crashed onto Angel Island. Knuckles encountered the ships creator and pilot, Dr. Robotnik, who convinced the somewhat gullible echidna that Sonic the Hedgehog and Miles "Tails" Prower, both on the doctor's tail, were evil-doers coming to steal the Master Emerald. In truth, Robotnik plotted to steal the Master Emerald himself and use it as a power source to re-launch the Death Egg.

During their adventures, Sonic and Tails stumbled upon the entrance to the Master Emerald's hiding place in the Hidden Palace Zone when Knuckles went to check on it. Riddled with questions upon seeing the massive gem, Sonic and Tails left to get answers. As Knuckles went to confront Sonic upon their arrival at the shrine, Robotnik made his move and stole the Master Emerald, much to Knuckles' humiliation at realizing he had been tricked.

The Master Emerald allowed Robotnik to relaunch the Death Egg, but Sonic and Tails got onboard his ship to reclaim the gem. Using a giant mech powered by the Master Emerald, Robotnik hoped to defeat Sonic, but he still lost and tried escaping with the gem into space. However, Super Sonic destroyed Eggman's final robot, and Sonic returned to the surface, Master Emerald in hand, and brought it back to Angel Island, allowing it to arise once again.

It was not long before that the Master Emerald was stolen again, this time by the Eggrobo, seemingly under the command of Mecha Sonic. Knuckles pursued the Master Emerald to Sky Sanctuary Zone where Mecha Sonic used the Master Emerald's power to attain it own Super State. However, because it was unable to properly maintain its Super State, Knuckles defeated Mecha Sonic and reclaimed the Master Emerald. Timing it perfectly. Sonic appearing in his biplane to help Knuckles back home and the Master Emerald was again brought back to Angel Island. In an alternate ending of the game, should all Chaos Emeralds fail to be collected, Knuckles would lose the Master Emerald after the battle, as Angel Island descends into the sea.

Sonic Adventure
The Master Emerald appeared again in Sonic Adventure for the Sega Dreamcast, where it was again shown keeping Angel Island afloat. The Emerald also held within it the ancient monster known as Chaos along with the ancient controller of the Master Emerald and the Chaos Emeralds, and an Echidna female named Tikal. In the game, it was shattered by Dr. Robotnik to release Chaos, causing Angel Island to fall. In the duration of the game's storyarc, Knuckles collects the shattered pieces of the Master Emerald from a variety of locations, and ultimately repairs the Emerald.

Sonic Adventure 2
The Master Emerald was again a source of contention as Knuckles fought with Rouge the Bat for possession of it in Sonic Adventure 2. Doctor Eggman tried to steal it again while they were distracted, but Knuckles purposely shattered the Emerald in order to keep it out of his hands. Knuckles and Rouge then set off separately to gather the shards of the Emerald for their own reasons. He managed to recover most of the Emerald shards, although after they briefly collided with an asteroid and opened up the cargo bay of a space shuttle, he was forced to ditch his friends (and nearly killed them by crashing the shuttle) in order to re-recover the lost emerald shards.

Once all the pieces had been collected the Emerald was reformed by Knuckles. When Space Colony ARK started to fall (due to an automatic system when all seven Chaos Emeralds were gathered in the central control room), Knuckles used the Master Emerald to try to stop the disaster in the Eclipse Cannon's Core, which resembled the Emerald Shrine on Angel Island, to negate the Chaos Emeralds' power.

Sonic Battle
When Sonic went to fight Emerl on the Death Egg in Sonic Battle, he brought the Master Emerald with him, hoping it would negate the Chaos Emeralds that powered Emerl. However, the Master Emerald was shattered by a crazed Emerl, as he was bothered by the light it produced. It was most likely put together again, as it appears in Sonic Advance 3, which is very likely situated after Sonic Battle.

When the Master Emerald appears, Sonic says "a Master Emerald!". This is most likely a translation error, especially because in the next sentence he refers to it as "the Master Emerald."

Sonic Heroes
The Master Emerald played no role in Sonic Heroes, but it was mentioned by Rouge the Bat in the last movie of Team Dark's Story. She says she "might as well go after that Master Emerald, since that irritating ECHIDNA is here!". Shadow responds, saying, "Some things never change, do they?", hinting that he managed to remember her rivalry with Knuckles. It is later hinted at in the ending of the final story, when Rouge the Bat mentions "stealing someone else's treasure," with Knuckles deducing after hearing the remark that she's going to steal the Master Emerald.

Sonic Advance 3
The Master Emerald then had a somewhat important role in Sonic Advance 3. After Eggman uses Chaos Control to split the world into seven parts, Sonic and Tails travel to the Master Emerald in order to use its powers to induce Chaos Control and undo the changes. After the heroes find it, the final boss is then fought at the Master Emerald altar. After the boss is defeated, the Master Emerald releases a bright light and repairs the world.

Sonic Rivals
In Sonic Rivals, Eggman Nega, masquerading as Eggman, stole the Master Emerald and used a special camera to turn it into a card, forcing Knuckles to find him and get it back. The game also stated that the Master Emerald exists in all moments in time simultaneously, so when Eggman Nega transformed the Emerald into a card in one moment in time, it disappeared from all other points in time. The Master Emerald is also one of the 150 collectible cards in the game.

Sonic Rivals 2
In Sonic Rivals 2, the Master Emerald was once again stolen. Working with Rouge, Knuckles uses an Emerald Detector he found to help locate the Master Emerald without luck, as it's revealed at the end of the game the Master Emerald is in fact inside the detector. It is also in the card "Knuckles and the Master Emerald", but strangely, only Knuckles is shown on the card. This is because it is a cropped image from Sonic Adventure.

Sonic Riders: Zero Gravity
Eggman mentions the Master Emerald in Sonic Riders: Zero Gravity when clearing Mission 4 of Astral Babylon with an Extreme Rank.

Sonic Chronicles: The Dark Brotherhood
In Sonic Chronicles: The Dark Brotherhood, Pir'Oth Ix uses the Master Emerald to create a gateway to the Twilight Cage and at the end of the game he uses either the Chaos Emeralds, the Master Emerald, or "the power of Nocturne itself" to achieve his Super State. Later, Knuckles takes the Emerald back.

Sonic & Sega All-Stars Racing
In Sonic & Sega All-Stars Racing, Knuckles' All-Star Move uses the Master Emerald. It is revealed that Knuckles can use the Master Emerald to absorb power. In this increased power state, Knuckles is able to fly above the ground and charge up energy in his right fist. This huge build up of energy allows him to punch the ground so hard that everyone on the track will be hurt and bounced up in the air. In this state Knuckles also has increased speed, which can be used to get closer to first place.

Sonic & All-Stars Racing Transformed
In Sonic & All-Stars Racing Transformed, the Master Emerald appears when Knuckles uses his All-Star Move. in this game, he can use the Master Emerald's power to use an energy attack similar to Shadow's Chaos Blast.

Sonic Runners
In Sonic Runners, the Master Emerald was hidden away by Knuckles in a lava temple, but was later stolen by Dr. Eggman. Once he caught news of this, Knuckles hunted Eggman down, but when Eggman tried to escape with the Master Emerald, Knuckles smashed it into several Master Emerald Fragments to prevent the theft. With its fragments scattered everywhere, Team Sonic began tracking them down while keeping them from Dr. Eggman and his lackey Metal Sonic. After a grueling hunt, Team Sonic got all the fragments back and Knuckles brought them back to the lava temple where he reassembled the Master Emerald. However, there was still the problem of guarding the Master Emerald from Eggman while Knuckles was away. Fortunately, the local Animals and Omochao offered their help and they proved their usefulness by driving off Eggman when he tried stealing the Master Emerald again.

Size dispute
The Master Emerald's size and shape seems to change over time; in games such as Sonic & Knuckles and Sonic Adventure, the Master Emerald is fairly larger than Knuckles, while in other games such as Sonic Adventure 2 and Sonic Chronicles: The Dark Brotherhood depicts it as being about the same size as a Chaos Emerald.

While these appearances may seem to contradict themselves, it is actually a demonstration of the Master Emerald's ability to change its size according to its owner's will. This is firmly demonstrated by Knuckles in Sonic Adventure 2: After Knuckles restores the Master Emerald, he is able to shrink it down to the size of his hand. Then, after Shadow defeats the Biolizard, Knuckles puts the Master Emerald into the core of the Space Colony ARK where he is able to enlarge it to a size slightly larger than himself.

Sonic the Comic
In Sonic the Comic, the Master Emerald is not an eighth emerald separate from the main group of seven, but is rather the green Chaos Emerald at the peak of its power. While it is the most powerful of them all, it does not have the powers to control the others, this role being filled by the Grey Emerald. As in other continuities, the Floating Island will fall out of the sky if it does not have the Master Emerald to power it, although this does not happen immediately, but rather over a course of hours.

Originally created by the Drakons, the Master Emerald was claimed by the Echidnas. During the next millennia, the Master Emerald and five of the Chaos Emeralds got split in two. On Mobius, they were targeted by Dr. Robotnik while Sonic and the Freedom Fighters kept them safe. In one of Robotnik's failed attempts to seize the Emeralds, the Master Emerald and the other Chaos Emeralds were rejoined with their missing halves and left on the Floating Island to be guarded by Knuckles. While multiple factions would come to the island seeking the Emeralds, Dr. Zachary's attempt shattered the Master Emerald and Knuckles had to contain its energies in a broken robot until he found a new emerald for them.

Archie Comics
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Master Emerald was created after Tails used the Chaos Syphon to collect the energies of Mammoth Mogul and Enerjak's Chaos Emeralds, and merge them with the two that were keeping Angel Island afloat. As a result, the Master Emerald has the power of fourteen Chaos Emeralds. As with the Chaos Emeralds that kept the Island aloft before it, the Master Emerald was protected by the Brotherhood of Guardians.

After its creation, the Master Emerald would be targeted by several villains, such as Dr. Eggman, Scourge the Hedgehog and Dr. Finitevus, all while the number of its guardians dwindled. It was also the only Emerald to be rescued from A.D.A.M.'s summons during the Great Harmony. When Dr. Finitevus used the Master Emerald to turn Knuckles the Echidna into the fourth Enerjak, Sonic use it to become Super Sonic to hold off Enerjak long enough for Locke to use the Master Emerald to restore Knuckles, though at the cost of his own life. After that, Knuckles remained as the only guardian of the Master Emerald left.

Following the Super Genesis Wave, the Master Emerald's origins and history match that of its game counterpart. During the Shattered World Crisis, Knuckles the Echidna was forced to shatter it to keep it from being taken, and spent the remainder of the crisis reassembling it.

Sonic X
In Sonic X, the Master Emerald is a powerful object originating from a parallel earth. Much like in the games, it is guarded by Knuckles the Echidna and it holds the power to control the Chaos Emeralds.

When Knuckles was transported to earth, he spent most of his time looking for a way back home to continue protecting the Master Emerald. Ironically, the Master Emerald came to him when it was transported to earth during a giant Chaos Control. There, it came under Knuckles' protection again. Eventually though, the Master Emerald and everything from its world were returned home when their presence threatened to freeze time.

Six months later, the Master Emerald was used to power the Blue Typhoon, which Sonic and co. used to travel around the galaxy and battle the Metarex. In the final battle with Dark Oak, the Metarex's leader, Knuckles was forced to sacrifice the Master Emerald, leaving it shattered and powerless for the time being

Trivia

 * In the Nick Arcade and Simon Wai prototype versions of Sonic the Hedgehog 2, there is a large green object shaped like an emerald in Hidden Palace Zone, which was often believed to be the Master Emerald. However, it was just a rock that Sonic could break to enter the tube that is below.
 * In the 2013 re-release, a spring would be hidden in it.
 * In Proto Palace Zone, the emerald object would warp the player back to the Level Select if he/she stood on it.
 * The Master Emerald that appears in Tikal's visions in Sonic Adventure is much darker than the Master Emerald that appear elsewhere in the game.
 * It also moves up and down in Tikal's visions.
 * In Sonic Adventure, after beating the game, the player can visit the Emerald Altar on Angel Island and see the incomplete Master Emerald with a small chunk missing (as a select few characters). However, in Knuckles' and Super Sonic's story, it is 100% complete.
 * The Master Emerald has been used to transform a character into a Super State at least twice in the game series. Once by Mecha Sonic in Sonic & Knuckles, and once by Ix in Sonic Chronicles: The Dark Brotherhood.
 * An accessory of the Master EmeraldAccEmeraldKnuckles.jpg was included with Knuckles late-2012 by Jazwares.
 * The Master Emerald is constantly being stolen, and was broken twice (Sonic Adventure, and in Sonic Adventure 2).
 * It was shown that Knuckles and maybe other guardians could change the size of the Master Emerald, as shown in Sonic Adventure 2 when it was about as big as Knuckles and Rouge at one point, and about the size of a Chaos Emerald in another. Or it was just a program mistake.
 * If the player performs a certain glitch with Tails in Sonic Adventure to get him through to the outside area of Angel Island, the Master Emerald would be completely gone from the altar.
 * It is possible that the Master Emerald, much like the Chaos Emeralds, is sentient. As Knuckles has been seen talking to the Master Emerald a few times and in Sonic Adventure, the Master Emerald showed Knuckles a holographic image of the Egg Carrier, where he found the remaining pieces of the Master Emerald.
 * The Master Emerald and the green Chaos Emerald, are the only two emeralds to be green like emeralds in real life.