This transformation exists primarily within the Sonic the Comic continuity.
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
At last! At last I have the Chaos Emeralds again! I am complete! I am... Perfect Chaos! — Perfect Chaos, Sonic the Comic #183
Perfect Chaos is a transformation that appears in Sonic the Comic. It is the transformed and completed state of Chaos, assumed by absorbing all seven Chaos Emeralds. Ascending to this form to achieve completeness was Chaos' ultimate goal, which he succeeded in with Dr. Robotnik's aid. Perfect Chaos then attempted to conquer Mobius, but was stopped by Super Sonic.
Unlike his more humanoid appearance in his base form, Perfect Chaos is a truly monstrous and nightmarish creature made of liquid chaos energy. In this form, Chaos takes the appearance of a large, bulky squid crossed over with a skull. It has a wide mouth with several sharp teeth, completely green and bulgy eyes and multiple squid tentacles. Also, inside its forehead, the seven Chaos Emeralds float around.
Having tracked the Chaos Emeralds to Robotnik's Retreat after Dr. Robotnik gathered them there with his Chaos Resonator, Chaos absorbed the emeralds after Sonic had returned from the past through him. With all seven Chaos Emeralds within him, Chaos at last became Perfect Chaos and began spreading his destructive influence across Mobius, intending to become the ruler of the planet. To Perfect Chaos' interest though, Sonic was able to fight his fear effect by focusing on his rage and began pulling the Chaos Emeralds out of him. However, even with the Freedom Fighters aiding Sonic, Perfect Chaos quickly repelled them and got the emeralds back.
As all seemed hopeless, Super Sonic arrived, who had been seeking out a source of chaos energy to recharge himself and save his own life. Perfect Chaos tried attacking him, but Super Sonic threw himself into its liquid body and completely drained him of chaos energy. Without any energy left, Perfect Chaos reverted back into a Drakon fish and was thrown into a lake by Super Sonic.
Powers and abilities
With the power of all seven Chaos Emeralds, Perfect Chaos is a thousand times stronger than his base form and is totally invincible. In this form, Perfect Chaos is able to manipulate reality to the extent of at least recreating an entire planet in his own image.
Being made of energy in a liquid form, Perfect Chaos is pretty much indestructible, as he can withstand any attack without being injured, and if dissipated, he can reconstitute himself again. He is also able to draw the Chaos Emeralds into him when they are close by, even after they are ripped straight out of him.
Just like his earlier form, Perfect Chaos possesses a fear effect which will cause feelings of extreme fear and panic in others when in close proximity to him, rendering them unable to fight back. The closer someone is to Perfect Chaos, the worse the fear and panic he can induce become. However, his fear effect can be bypassed by focusing on one's own emotions such as rage.