Shadow the Hedgehog

Shadow the Hedgehog is the end result of Project Shadow, an effort to create the Ultimate Lifeform. Created by Professor Gerald in his efforts to find a cure to a rare disease affecting his granddaughter Maria, Shadow was gifted with the powers of the alien Black Doom through that entity's blood. After the project was forcibly shut down by the government, Shadow was put into stasis for 50 years and then awakened by Dr. Eggman, Gerald's grandson, to help him take over the world. Shadow sought instead to destroy the world to avenge Maria, who had been killed by the raid on Space Colony ARK where they had both lived. However, Sonic the Hedgehog and his friends were able to convince Shadow that Maria would not have wanted such a result, and Shadow joined forces with Sonic to save the planet. Saved by aliens, he would return to join with Sonic and others against the evil Xorda. He would eventually rejoin Eggman, only to turn against him and join the special forces of the United Federation after learning of the purpose Gerald had created him for.

50 Years Ago
Shadow was created by Professor Gerald as part of Project Shadow, Gerald hoping that through Shadow he could find a cure for his granddaughter Maria's Neuro-Immune Deficiency Syndrome. Failing to develop a successful Ultimate Lifeform on his own, he turned to Black Doom, leader of the Black Arms alien species. Using Doom's blood, he was able to complete his process and create Shadow, at the same time granting Shadow some measure of Doom's immense powers. However, when the experiment failed to produce Maria's cure-and Gerald learned of Black Doom's malicious intentions for Mobius-Shadow was modified so that when the Black Arms eventually returned, he would be waiting to defend Mobius from them. (StH: #98, #171)

However, tragedy struck soon afterwards, as a government task force raided Space Colony ARK, the space station where Shadow was created and lived with Maria and Gerald. With Maria's death and Gerald's arrest, Shadow was left bitter and angry. Reuniting with Gerald by some means, he was put into stasis and given a new purpose: to avenge Maria's death by destroying the inhabitants of Mobius. (StH: #98)

Awakening
When Shadow was awakened from stasis 50 years later, it was by Gerald's grandson Julian. Coveting Shadow's power so that he could take over the world, Eggman enlisted Shadow's aid in acquiring the Chaos Emeralds. Shadow proceeded to steal Station Square's Chaos Emerald, after facing off against the city's protector Silver Sonic II. Due to his similar appearance to Sonic, Station Square's army believed the theft to have been Sonic the Hedgehog, and thus sent their military after him instead. (StH: #98)

Shadow was believed to have been killed, though in actuality he was saved by the benevolent Bem as they investigated Mobius from orbit. Upon awakening, the Bem transformed Shadow into his super form to combat the arriving Xorda warship. Despite his powers, the Xorda ship managed to shoot down the Ultimate Lifeform, hurling him into Mobius' gravitation pull. After landing on the planet's surface, Shadow was discovered by the Knothole Freedom Fighters and formed a temporary alliance with them. Together, they learned that the Xorda were intent on destroying Mobius for crimes committed by its inhabitants made back when the planet was known as Earth. Together with a veritable army of other Mobians, Shadow charged the Xorda Quantum Dial weapon, seeking to destroy it before it wiped out Mobius. Thanks to the efforts of Sonic, who seemingly imitated Shadow in sacrificing his life, the weapon was destroyed. (StH: #124, #125)

Shadow spent the time of Sonic's absence searching for meaning in his life, eventually confronting Dr. Eggman with the intention of killing him. Eggman escaped, and Shadow then found himself drawn to Hope Kintobor, Eggman's niece and a girl who reminded Shadow strangely of Maria. While watching over her, Shadow was abducted by Locke, the father of Knuckles the Echidna, who believed that Shadow's strange nature-somehow alive despite being neither animal, vegetable, or mineral-could somehow help him to locate his missing family, the members of the Brotherhood of Guardians. Not taking kindly to Locke's interrogations, Shadow attacked him, only to be halted in his vengeance by Hope, who had been pulled along as Locke teleported Shadow to a hidden location. (StH: #132, #133, #145)

Wandering once more, Shadow found a hidden laboratory that had existed since before the Xorda attack on Earth, meeting a robot named Isaac with detailed knowledge of Mobius' history. The two eventually became involved in a three way battle with Sonic and a new Metal Sonic built by Dr. Eggman. When the trio discovered that the base harbored an ancient and powerful missile, Shadow aided Sonic in preventing the missile from launching. Shadow assisted in getting Sonic to safety after the latter's ankle was wounded, then disappearing once again. (StH: #146, #147, #148, #149)

Allegiance with Eggman
With the battle ended, Shadow went out on his own once more, eventually locating Gerald's lost diary. However, Shadow was once again engaged by Metal Sonic, the two being rendered unconscious during the ensuing battle and brought back to Eggman by Mecha. Once in Eggman's presence, the mad-scientist was able to convince Shadow to work with him by informing Shadow that Maria was his half-sister. (StH: #157, #158)

When A.D.A.M. secretly seized control of Knothole's Metal Sonic Troopers and directed them to attack first Eggman and then their creators, Shadow joined Sonic, the Freedom Fighters, and the Chaotix in resisting the enemy. Hope was harmed during this conflict as she lived in Knothole, and Shadow became motivated by fury over her coming to harm. Using his link to the Chaos Force, he defeated the Troopers with Chaos Control, intriguing Knuckles in the process. Grateful for Sonic helping Hope, Shadow chose not to antagonize him but instead departed, returning to Eggman. (StH: #157, #158, #159)

He would later return on Sonic's birthday to express his thanks, joining in battle with him against Scourge the Hedgehog and Croctobot. The latter, another servant of Eggman's, threatened to tell Eggman of Shadow's treachery, but all three Hedgehogs put aside their rivalry to destroy the robot together. Shadow and Sonic found themselves initially outmatched by Scourge, who left with Rouge the Bat in tow as the Freedom Fighters arrived to back up his enemies. Shadow pursued them, but they escaped with the assistance of an Echidna mad scientist named Dr. Finitevus. (StH: #160, #161)

A.D.A.M. would later divert Shadow's attention by releasing Mammoth Mogul and Ixis Naugus-both of them recently taken prisoner by Eggman in the Egg Grape Chamber-and forcing Eggman to dispatch Shadow after them. Shadow was then lured into a trap by A.D.A.M., who used his abilities in conjunction with Tails' to summon all the Chaos Emeralds from across the universe to Mobius. While Sonic faced A.D.A.M., Shadow-in Super form-joined with Turbo Tails to send all the gathered Chaos Emeralds to the Zone of Silence, getting them out of reach of both A.D.A.M. and Eggman. (StH: #168, #169)

Shadow would then depart with Eggman, but soon their alliance would end. After taking Professor Gerald's diary from Eggman and yanking out his nephew Snively's hairs in the process, Shadow sought the Freedom Fighters for help deciphering it, only to have it damaged on his way to Knothole. Taken into the disk by NICOLE, the artificial intelligence member of the Freedom Fighters, Shadow made contact with virtual duplicates of Gerald and Maria and learned of his purpose in fighting Black Doom. Afterwards, Shadow went his own way, leaving Eggman behind to prepare for his eventual destiny. (StH: #171)

Agent of G.U.N.
Not long after his desertion of Eggman, Shadow joined the special forces of the United Federation along with Rouge the Bat. Responding to a distress call from New Mobotropolis, the city to which the inhabitants of the Kingdom of Acorn relocated after Knothole was destroyed. They had come under assault from Enerjak, a brainwashed Knuckles with the power of the Master Emerald infused within him by Dr. Finitevus. With his typical confidence, Shadow confronted Enerjak in a battle of Chaos powers, but soon realized that he had met his match. Removing his inhibitor rings to boost his power, he attacked Enerjak with increased strength, but soon burned himself out without much success against the super-powered Echidna. Shadow and the rest of the people of New Mobotropolis were only saved by the arrival of the Egg Fleet, which hit Enerjak with teleportation beams to send him to New Megaopolis to have his power drained. Shadow, his obligation fulfilled, departed to return to the United Federation. (StH: #182)

Personality
Shadow is arrogant, aloof (shallow), doesn't take kindly to others interfering in his business, and cares for who he wants to care for. He lacks many of Sonic's inhibitions, being perfectly willing to eliminate a foe rather than merely subduing them. Still, he does have a small sense of honor, enough to leave the Freedom Fighters in peace on some occasions despite his alliance with Eggman. At times he has behaved with almost a mercenary attitude, joining forces with others only to further his own goals, but in the end he usually ends up picking the side of moral right. When Shadow has a goal, he sticks to it without hesitation, not resting until it is fulfilled.

Powers
Possessing speed equal to Sonic, Shadow also commands Chaos powers through a direct link to the Chaos Force, which unlike that of the Brotherhood of Guardians doesn't require tapping into the energies of the Master Emerald. Shadow can utilize these powers in a variety of ways, most commonly in the form of attacks such as Chaos Spear and Chaos Blast, or in time-freezing and teleportation moves such as Chaos Control. Despite his power, Shadow has his limits, and does not possess the same level of energy Knuckles once wielded. He can temporarily increase his powers by removing his inhibitor bands, but after the effects wear off he is left weakened.

Background information
In the game universe, Shadow was saved by one of Eggman's robots, but this hadn't been revealed yet so former head writer Karl Bollers came up with the idea that he was saved by the Bem for Shadow to appear in the comic.