Perfect Chaos

Perfect Chaos (パーフェクトカオス) is the final boss of Sonic Adventure and the second boss on the console/PC version of Sonic Generations. It is the Super State of Chaos, assumed by absorbing the negative energies of the seven Chaos Emeralds.

Around 4,000 years ago, Chaos assumed this form to destroy the Knuckles Clan and the rest of the world in vengeance, but was sealed away in the Master Emerald by Tikal. Four millennia later, when Chaos returned due to Dr. Eggman, it became Perfect Chaos again and continued its rampage until it was defeated and calmed down by Super Sonic.

Appearance
Vastly more different than any of Chaos' previous forms, Perfect Chaos is a several-stories-tall monster composed entirely of pure chaos energy in liquid form. Its main body resembles a thick snake whose head, back and sides are covered in dark blue reptilian skin while its underbelly is clear liquid, and it has pointy liquid spikes protruding from its back. It possesses a large mouth with green razor-sharp teeth and a green tongue that extends far beyond its eyes, which are green and have slit-like pupils. It also has flaps of skin hanging from just behind its eyes, green horns on its nose area and behind its eyes, and a "fin" on top of its head containing its organic brain. Also, running from the base of its body to its back spikes and brain are green-glowing arteries. The base of its snake-like body ends in a flood of liquid with several liquid-composed tentacles extending from it.

In Sonic Adventure and its remakes, Perfect Chaos' entire body is composed of liquid, with no distinction between the different sections of its skin, and the spikes on its back are merely blunt extensions of its "flesh". It also lacks any green coloration (except for its eyes) and arteries, and the base of its body merges with the water below it in a huge cyclone with only two tentacles extending from its base.

Past
4,000 years ago, chief Pachacamac of the Knuckles Clan and his men attacked the Altar of the Emeralds, home to Chaos and its family of Chao that it protected, to seize the Chaos Emeralds and Master Emerald there to further their war efforts, injuring both the Chao and their friend Tikal in the process. In a fit of anger and sadness over these actions, Chaos used the Chaos Emeralds to become Perfect Chaos and destroyed Pachacamac and his men, along with their civilization and nearly their entire clan overnight. However, Perfect Chaos, now corrupted by rage and hatred, would not stop its rampage and would have destroyed the rest of the world had it not been for Tikal, who sealed herself and Perfect Chaos inside the Master Emerald, returning Chaos to normal.

The effects of Perfect Chaos' first attack would over time have a significant impact on the world, such as the creation of Angel Island, the slow terminal decline of the Knuckles Clan, and the ascendancy of the Nocturnus Clan within the ancient world.

Sonic Adventure

 * See also: Perfect Chaos (Sonic Adventure)

In Sonic Adventure, Chaos was freed by Dr. Eggman who sought to transform it into Perfect Chaos and use it as a weapon to destroy Station Square and build Eggmanland on it. Still brimming with rage, Chaos remained under Eggman's command while the doctor collected the Chaos Emeralds so it could continue its rampage. When Eggman failed, Chaos rebelled against Eggman and went after the Emeralds itself, eventually becoming Perfect Chaos again.

Perfect Chaos soon after appeared in Station Square and began destroying it with a destructive flood. Shortly into its rampage, Perfect Chaos faced a vengeful Dr. Eggman in the Egg Carrier 2. However, Perfect Chaos shot down the vessel with a single energy beam. At that point, Perfect Chaos had absorbed all the negative chaos energy from the Chaos Emeralds and expelled them. This act proved to be Perfect Chaos' own undoing however, as Sonic the Hedgehog harnessed the Chaos Emeralds' positive energies to transform into Super Sonic and defeat Perfect Chaos. With its defeat, Perfect Chaos reverted back to normal and its anger was neutralized by Super Sonic's power, returning it to the peaceful creature it once was.

Mario & Sonic at the Olympic Winter Games
Perfect Chaos makes a cameo as an ice sculpture in Mario & Sonic at the Olympic Winter Games during the Dream Figure Skating competition in Sonic Land. In this event, which mimics the battle against Perfect Chaos in Sonic Adventure, the participants battles the ice sculpture of Perfect Chaos as a part of their performance until it is obliterated.

Sonic Chronicles: The Dark Brotherhood
In Sonic Chronicles: The Dark Brotherhood, Perfect Chaos is mentioned by several characters at different points in the story, most noticeably about how Perfect Chaos' destruction of the Knuckles Clan allowed the Nocturnus Clan to reign supreme in the ancient world before they were banished to the Twilight Cage. Perfect Chaos is also given a profile in the codex in the game's Journal and is mentioned in several other entries as well.

Sonic Generations
Perfect Chaos serves as a boss in the game Sonic Generations, and is the main boss of the Dreamcast era. The player does not use Super Sonic in this game. Instead, the player uses Sonic and must navigate three different kinds of paths, each involving going into Perfect Chaos and coming out the top end, which damages it. Its last resort is sending platforms out of the water. These platforms fall after an allotted time, so the player must hurry and avoid falling off, and Homing Attack the top of it to end the fight.

Powers and abilities
With all the negative chaos energy from the seven Chaos Emeralds, Perfect Chaos accordingly commands ultimate power and has access to unlimited energy. It is described as a mysterious and higher being in this form and possesses unprecedented size and power on a god-like scale which is said can easily lay waste to the entire world.

Perfect Chaos' hydrokinetic powers in this form have been enhanced to unprecedented heights, reaching the point where it can control entire floods and flood Station Square in a matter of seconds using colossal tidal waves and local water sources. It can as well manipulate water in a more delicate manner, such as conjuring up tornadoes of water or creating water sprouts strong enough to keep entire roads suspended in midair.

Being made of liquid chaos energy, Perfect Chaos is nearly indestructible and can mimic the properties of water. It has complete control over its physical structure, allowing it limited shapeshifting, such as elongating its tentacles for greater range, changing its shape into fluid liquid, and if dissipated, it can reconstitute itself again. Additionally, it can merge with the water around it, allowing it to become one with its floods. Due to its size, Perfect Chaos has enormous strength, destroying entire buildings with just one strike with its tentacles.

Perfect Chaos has the ability to project highly destructive energy in different ways. It can fire an immense energy beam from its mouth which packs enough power to destroy the Egg Carrier 2 with a single shoot, shot energy bullets from the spikes on its back which can decimates entire buildings and project clusters of energy balls.

Weakness
Perfect Chaos' weak point is its brain. Whenever it is struck, it not only causes Perfect Chaos great pain, but also makes its entire body structure weaken and crumble. This is a highly vulnerable spot, as Sonic was able to defeat Perfect Chaos in Sonic Generations without becoming Super Sonic by attacking its brain.

Archie Comics
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, Perfect Chaos appeared as a part of the comics' adaption of Sonic Adventure. Like in the games, Chaos became Perfect Chaos when the Knuckles attacked its home, but was stopped by Tikal and the Servers who sealed it in the Ancient Onyx.

Centuries later, Chaos was freed by Dr. Eggman whose sought Perfect Chaos' power. Eventually however, Chaos rebelled and became Perfect Chaos once more. Perfect Chaos then began laying waste to Station Square, but thanks to Tikal, Super Sonic and Knuckles, Perfect Chaos was defeated and returned to its normal, peaceful state.

After the timeline was rebooted due to the Super Genesis Wave, Perfect Chaos' history became identical to its game counterpart.

Sonic X
In the anime series Sonic X and its comic series published by Archie Comics, Perfect Chaos appeared as a part of the series' adaptation of Sonic Adventure. In this media, Perfect Chaos has an increased "back" size and several new tentacles. It also possesses additional abilities, like absorbing attacks, creating crystal spires of water and generate force-fields.

Much like in the games, Chaos transformed into Perfect Chaos to destroy Pachacamac and his tribe after they forcefully invaded its home. It would not stop its rampage though, so Tikal sealed it inside the Master Emerald. Generations later, Perfect Chaos emerged again, this time on earth, due to Dr. Eggman, but it was defeated and calmed by Super Sonic.

In the comic series, Perfect Chaos appeared again when Dr. Eggman forced it to transform while fusing it with his Greenbots, creating the machine-hybrid Chaosbot which obeyed his commands. However, Perfect Chaos had free will restored and its body released from the robots thanks to Super Sonic.

Sonic the Comic
In Sonic the Comic, Perfect Chaos appeared as the series' final foe. In this media, it resembles a large, bulky squid and possesses additionally abilities, including a fear effect and reality warping.

After Dr. Ivo Robotnik gathered the Chaos Emeralds with his Chaos Resonator, Chaos followed the emeralds there and appeared before them when Sonic and his friends confronted Dr. Robotnik. Chaos quickly absorbed the Chaos Emeralds, becoming Perfect Chaos, and began reshaping Mobius in his own image. All seemed lost, as Sonic and his friends were unable to stop Perfect Chaos, but then Super Sonic arrived and defeated Perfect Chaos by jumping into him and absorbing all of his chaos energy, thus returning him to his original Drakon form.

Trivia

 * It has been explained that Perfect Chaos' design in Sonic Generations was how it was originally meant to look like in Sonic Adventure, but due to the technological restraints with the Dreamcast at that time, it was not possible.
 * The song Open Your Heart is played during the battle with Perfect Chaos and a remix is played in Sonic Generations.
 * Perfect Chaos's roar in Sonic Generations sounds more like a shriek than a roar.
 * Perfect Chaos's destruction of a city, large appearance and powerful attacks such as a mouth beam makes Perfect Chaos highly reminiscent of Kaiju, giant monsters portrayed in Japanese media such as the creature Godzilla. In particular, Perfect Chaos bears a resemblance to the Kaiju Biollante from the Godzilla film series.
 * Until Sonic the Hedgehog, Perfect Chaos was the last main villain/final boss to directly use the Chaos Emeralds to transform: The Biolizard instead merged with the ARK after using Chaos Control, Metal Madness/Metal Overlord was not shown using the Chaos Emeralds to transform (and the former was explicitly stated to have not used the Chaos Emeralds by Dr. Eggman), and Black Doom admitted that he underestimated the Chaos Emeralds' powers during his fight as Devil Doom.