Chaos Shadow

Chaos Shadow is a super form that is triggered when Shadow the Hedgehog takes off his Inhibitor Rings from his wrists. In this form, Shadow can use an unlimited supply of Chaos Energy even without the Chaos Emeralds. He turns into a reddish-yellow hue when having this form and, for a strange reason, he has no eyes.

History
When Sonic, Shadow, and Rouge were trying to stop the Doom Laser from getting into a position to fire at the Freedom Fighters, Shadow thought it was impossible to stop it. He then took off his Inhibitor Rings, gave them to Sonic, and ran in front of the laser. He turned into Chaos Shadow and used Chaos Control to stop the machine. (SU #2)

Trivia

 * The official name for this super form was unknown up until the Sonic Universe "The Shadow Saga" trade-paperback was released, giving a bio on Shadow and stating this form of Shadow.