Nearly every Sonic game requires you to collect the Chaos Emeralds. Usually, they are used by Eggman to give him the power he needs to conquer the world. It's your job to nab them back. And when you collect all seven of them, you become Super Sonic, save the world, defeat Eggman, yadah, yadah, yadah... That's the way its been for years. But in 2001, the Chaos Emeralds have provided a different role in the Sonic series with the introduction of Shadow.

Chaos Control
-Shadow has the unique ability called Chaos Control. By using a Chaos Emerald, Shadow has the power to slow time down to a near halt, making him, in a sense, faster than anything else around him. Even Sonic. While Shadow is using Chaos Control, it seems to others that he is warping from place to place, when in reality he is simply moving extremely fast.
In the ShadowTH game, Chaos Control is used to excel Shadow through a stage at high speed for a short period of time. In a boss battle, it is used to slow down the action so Shadow can make and/or evade an attack.

Chaos Spear
-A move used by Shadow in Sonic Adventure 2. Using the power of the Chaos Emerald, Shadow can send a spear of chaos energy into his opponent, causing damage and knocking the rings out of him/her.

Chaos Blast
-Introduced in ShadowTH, Chaos Blast is a powerful move that Shadow uses which destroys all obstacles and enemies within a specific range. The use of this move opens up blocked pathways and heavily damages or destroys almost any enemy.