*Shadow the Hedgehog is a character in the Sonic series with a complex story that involves genetic engineering, a deadly illness, and a quest for revenge:

Creation Shadow was created by Professor Gerald Robotnik as part of a secret government project to cure his granddaughter Maria from a deadly illness.

Trauma Shadow and Maria formed a strong bond, but the government deemed Shadow a threat and killed Maria while he was trying to protect her. Shadow was put into suspended animation and presumed dead.

Revival Shadow was revived by Gerald's grandson, Doctor Eggman, who wanted to use Shadow to conquer the world. Shadow agreed to help Eggman, but later remembered his promise to Maria and allied with Sonic to stop Eggman.

Amnesia Shadow often suffers from amnesia and is manipulated by other characters.

Missions In the games, Shadow completes "Hero" missions to help Sonic and his friends protect Earth, or "Dark" missions to help Doctor Eggman or Black Doom.

Choice In some games, players can choose how Shadow progresses through the game, such as whether to protect the planet, gather the Chaos Emeralds, or search for answers.

Shadow is usually depicted as an antihero who eventually chooses to ally with Sonic and his friends.*