User:Tezero/Tempspace

Setting, backstory, and characters
Sonic Adventure 2 is set on a fictional version of Earth populated mostly by humans and normal animals, but also by anthropmorphic animals. Besides its moon, the Earth is orbited by a giant, abandoned space colony called the ARK, where the government of an unnamed nation carried out research experiments until fifty years prior to the events of the game. A scientist named Gerald Robotnik worked there to

Story
After learning of a secret weapon from Gerald's diary, Eggman infiltrates a high-security G.U.N. facility in search of it. This weapon, a black hedgehog named Shadow who claims that he is the "Ultimate Life Form", offers to help Eggman take over the world, telling him to meet him at the abandoned Space Colony ARK with more Chaos Emeralds. Shadow then goes to Central City, where he steals an Emerald and ends up running into G.U.N. soldiers. He experiences a flashback to the death of a girl named Maria, begging him to fulfill an unspecified promise, which he interprets as a promise for revenge. He then blasts through the military forces and ends up confronting Sonic, whom the military had mistaken for Shadow. After a brief confrontation, Shadow escapes and G.U.N. captures Sonic.

Meanwhile, Knuckles confronts both Rouge and Eggman, who each attempt to steal the Master Emerald. Knuckles shatters the Emerald to prevent this, then proceeds to search for the scattered shards. While Rouge intends to collect the shards for personal benefit, she must also accomplish a mission for the government to spy on Eggman. This mission leads her to Eggman's base, and eventually the ARK. Onboard, Shadow reveals to Eggman a superweapon called the Eclipse Cannon, also created by Prof. Gerald. He then relays his plan: use the Chaos Emeralds to charge the Eclipse Cannon, and utilize its destructive power to take over the world. Rouge then appears and joins the two in their search for the Emeralds.

Tails and Amy infiltrate G.U.N.'s island base and rescue Sonic while Eggman, Shadow, and Rouge collect three Emeralds on the island. Eggman then broadcasts his threats across the world and demonstrates the Cannon's power by destroying half of the moon. Sonic and company use their Emerald to track down the other six, with Knuckles coming along as well. Together, the group infiltrates Eggman's base, boarding Eggman's shuttle as it launches into space. Knuckles' Emerald shards are spilled along the way, and he leaves to collect them. He encounters and fights Rouge again, but after he saves her from falling into a lava pit, she nonchalantly surrenders her shards and Knuckles restores the Master Emerald.

Aboard the ARK, Tails reveals that he has created a counterfeit Chaos Emerald designed to reverse the energy fields of the real ones. However, when Sonic goes to place the fake Emerald into the Cannon, Eggman announces that he has captured Tails and Amy, causing him to go back and rescue them. Sonic tries to trick Eggman with the fake, but Eggman traps and jettisons him in an escape pod rigged with explosives. Using the fake, Sonic manages to perform the "Chaos Control" technique and escape, but Tails, thinking Sonic is dead, fights and takes down Eggman. Shadow is then sent to intercept Sonic before he destroys the Eclipse Cannon, but does not succeed.

After being defeated by Tails, Eggman manages to sneak away with an Emerald and goes to put it in the Eclipse Cannon. However, when he attempts to fire the Cannon at full power, the ARK begins to fall toward Earth, and a recorded message from Gerald Robotnik is broadcast worldwide: he programmed the ARK to collide with Earth and destroy it, as revenge against humanity. It is also revealed in his diary that this hatred began when the government condemned his research and killed numerous colleagues, including his granddaughter Maria, when attempting to shut the ARK down. Eggman determines that the Emeralds' energy is causing the ARK to plummet, and everyone works together to get to the cannon's core and neutralize the energy.

Shadow refuses to participate, but Amy pleads for his help, reminding him of Maria's true request: for him to help mankind. Realizing this, he catches up with Sonic and Knuckles, where they encounter the Biolizard, a prototype of the Ultimate Life Form. Shadow temporarily defeats it, allowing Knuckles to deactivate the Chaos Emeralds using the Master Emerald. However, the Biolizard uses Chaos Control to fuse with the cannon, becoming the Finalhazard and continuing the ARK's collision course.

Using the power of the Chaos Emeralds, Sonic and Shadow transform into their super forms and defeat the Finalhazard, then use Chaos Control to teleport the ARK back into a stable orbit around Earth. However, the process depletes Shadow's energy and he plummets to Earth, content that he has fulfilled his promise to Maria, and is presumed dead. As the humans back on Earth celebrate, the two teams reflect on the events that have transpired, and as they leave the station, Sonic bids a final farewell to Shadow.