Shadow the Hedgehog

Shadow, also known as Shadow the Hedgehog is a major character Sonic the Hedgehog videogame series and other adaptations. He is also somewhat Sonic's sworn enemy in Sonic Adventure 2, but he ends up to befriend Sonic, though both the hedgehogs looked similar, and their animosity was toned down somewhat into a rivalry.

Personality
Shadow is a loner, to put it bluntly. He is rarely seen with others for an extened period of time, and distances himself from essentially everyone. He is usally soft-spoken, and only says what he needs to before a fight. If Shadow makes a threat, he has every intention of carrying it out. Shadow constantly refers to himself as the Ultimate Lifeform, and is extremely arrogant and self-absorbed, belittling his opponents and insulting their lack of strength. When first appeared, he was under mind control and couldn't do much to fight it, but have overcome this.

Biography
Fifty years before the events of Sonic Adventure 2, a top-secret project known as "Project Shadow" had begun on the Space Colony ARK. Led by Professor Gerald Robotnik, it was a government-sanctioned initiative to create "The Ultimate Lifeform," an immortal being that could be used for the benefit of the nation, likely in a militaristic fashion. While Gerald had initial misgivings to the purpose of the research he was assigned to, he realized that his results might be able to save his granddaughter, Maria. Suffering from the incurable disease Neuro-Immune Deficiency Syndrome, Maria only had a short time left to live, and Gerald was willing to do whatever it took to save her life. Going against his worries of stepping into territory man had no business playing with, the professor immediately began work, hoping that he could apply any newly-gained knowledge to find a cure to N.I.D.S.

Even with the resources at his disposal, Professor Gerald was unable to make significant progress. Without alerting anyone, Gerald decided to plea to the stars for help, contacting the Black Arms race. An alien civilization that lived upon the Black Comet, a celestial object that passed near the planet every fifty years, its leader Black Doom offered to assist Gerald in his quest. He offered his blood - which ended up being the key to perfect the ultimate lifeform - in exchange for the seven Chaos Emeralds, which he would collect the next time he passed through. Knowing that the Black Arms' intentions were less than desirable, Gerald made the deal regardless, and was able to successfully create Shadow the Hedgehog.

Once brought to life, Shadow immediately befriended Maria, and they became close during their short time together. Gerald, meanwhile, made precautions for the return of the alien race, ensuring that the Eclipse Cannon - an extremely powerful laser built into the ARK - was compatible with the seven Chaos Emeralds, so that when they did return humanity would be able to defend itself instead of bowing to their whims.

However, Gerald's progress was ruined when it was leaked to G.U.N. how he was able to create the successful prototype. During the meeting between Gerald and the Black Arms, one of the other children aboard the ARK had accidentally seen what transpired, and reported back to those in charge. As ties between the ARK and the United Federation had already been strained, hearing the news of the dealings with an alien race scared those in charge. Afraid of the implications, it was decided to launch an invasion and put a stop to the work being done there.

What happened next was nothing short of madness, as G.U.N. troops descended onto the ARK, causing chaos and confusion wherever they went. Immediately they went after the Biolizard, which they thought was the successful "Project Shadow" prototype, and in the process of putting the creature into stasis lost quite a few soldiers. From there they went about doing damage control, shutting down everything, getting everyone off the ARK, and killing those who resisted if need be. Knowing that the G.U.N. forces would be there at any moment, Maria convinced Shadow to enter an escape pod, her final wish to him that he give the people on the planet a chance to be happy. Wishing him goodbye, Shadow could do nothing as he watched the G.U.N. soldiers storm into the lab, firing a shot which would forever change the hedgehog's life.

Learning of his granddaughter's death, Professor Gerald soon went mad, swearing vengeance on humanity for taking away the only thing that ever meant anything to him. Though just what exactly transpired is cloudy, what is known is that both Gerald and the escape pod that held Shadow were gathered by G.U.N., Shadow being placed in cryogenic storage within Prison Island, and Gerald being incarcerated and charged with the crimes that happened aboard the ARK.