Perfect Dark Gaia

"When the beast is complete, its dark arms shall encompass the planet, ushering in the end of times. The world, in death, will fall into a deep sleep in waiting for the time of rebirth to come."

- Gaia Manuscripts, 4:28, Sonic Unleashed

Perfect Dark Gaia (パーフェクトダークガイア) is the completed form of Dark Gaia and the final boss of Sonic Unleashed. Every time Dark Gaia reaches the peak of its maturity, the beast assumes this grotesque form. As such, this form is the representation of the beast's true nature as a deity of darkness and destruction.

Dark Gaia assumed this form during its battle with Sonic the Hedgehog and the Gaia Colossus when it reached full maturity during the course of the battle, but was eventually defeated by the combined forces of Super Sonic and the Gaia Colossus.

Appearance
Basically, Perfect Dark Gaia is identical to its immature Dark Gaia form, except that it now has gained extra features. Once matured, it grows four extra, identical arms, giving it a total of six arms. Its large mouth, which makes up most of its head, has been opened, revealing hundreds of tiny tongues which give way to reveal seven green eyes; three smaller eyes in each side and one large, central eye where its (former) visual mouth once was. It also gains two more tongues, which hang out from each side of its central eye, similar to a dog's tongue, as well as a more human-like tongue barely visible below it.

Its seven tentacles (seen only in the 360/PS3 version) move down from its spine to below the magma that it resides in. Their ends also gain more shape as well, resembling a serpent head with a small mohawk, and each with one green eye in their mouth.

History
Perfect Dark Gaia has been the true form of Dark Gaia ever since the creature's birth in the beginning of time. Since the beginning of its conflict with Light Gaia, Dark Gaia would assume this form when it had reached full maturity within the earth's core and then rise from it to destroy the world, but would then be defeated by Light Gaia and resealed back in the core. In the following battle, Dark Gaia would lose this form and return to sleep inside the earth's core to gather up enough strength to become Perfect Dark Gaia again.

In the beginning of Sonic Unleashed , Dark Gaia was interrupted in this process due to Dr. Eggman's awakening it prematurely with his Chaos Energy Cannon, resulting in Dark Gaia breaking apart and had to be reassembled. When Sonic and Chip's battle with Dr. Eggman's Egg Dragoon led them to Dark Gaia's location, Dark Gaia reabsorbed the final fragment of its power from Sonic's Werehog form, and it became physically complete, but it was not until after the initial battle with Sonic and the Gaia Colossus (Chip's transformation) that it fully regained its lost powers and at last became Perfect Dark Gaia.

Finally having become complete, Perfect Dark Gaia was now ready to cast the earth into darkness and destroy the planet, but Sonic used the Chaos Emeralds to transform into Super Sonic and engaged Perfect Dark Gaia alongside the Gaia Colossus. At the end of the battle, Perfect Dark Gaia was defeated and fell into the earth's core, where it once again returned to sleep while its dark energy that had been covering the earth dissipated.

Powers and abilities
Perfect Dark Gaia possesses the same powers as its premature form, but can use them in a more refined and focused manner due to reaching full maturity. Being at the peak of its power, Perfect Dark Gaia stands as one of the most powerful beings in the series, being able to injure a Super State through brute force alone. Additionally, it could fight Super Sonic to the point where he fainted from exhaustion, something no one has been capable of, while taking on Light Gaia who is supposedly just as powerful as itself.

Like before, Perfect Dark Gaia has immense levels of super strength, capable of completely immobilizing the Gaia Colossus in its grip and overpower said foe in extended hand-to-hand combat. Likewise, it is capable of projecting extremely powerful energies into a variety of attacks; its can shoot large beams from its central eye, project purple orbs, launch black balls with paralyzing effects, and channel its energies into its claws for enhanced slashes. It can as well channel its energies through its tentacles to form a force-field around itself that not even Super Sonic can break through, though destroying the tentacles will lower the shield. Unlike its immature form though, Perfect Dark Gaia does not lose focus when charging its energies when attacked and can launch its beams at a much faster rate.

Perfect Dark Gaia has vast telekinetic powers that lets it pick up enormous balls of magma and throw them, and, like its premature form, has such a resistance to heat that it can touch magma without being burned.

Weakness
Perfect Dark Gaia's weak points remains its various green eyes, like its earlier form, which are highly sensitive to damage. Though not to the same extend as its eyes, its arms are as well vulnerable enough to be temporarily paralyzed with a well-aimed Super Sonic Boost. It is also not immune to its own power, meaning it will take damage from its own energy attacks should they be knocked back.

Wii/PS2 Version
This battle is lengthy and tough. The player need to move around the screen, collecting rings to ﬁll up Boost Gauge and dodging Dark Gaia’s attacks. While the player collecting rings, the player must avoid Dark Gaia’s claw attack. As the beast cocks its arm back, a faint slash ﬂashes onscreen, illustrating where the attack will land. The faint slash is followed quickly by the actual attack. If you’re wounded, the player lose the majority of the rings player collected thus far. Collect enough rings and when prompted, perform the Super Sonic Boost. As the player speeds toward the main goal of reaching the eye, dodge the ﬂoating debris. If successful, you wound the eye and start the process over again. As the player defeat more and more eyes, the player must move around the screen to target the remaining ones. Move in the direction of the still-open eye, and when it’s in front of the player, the onscreen attack prompt will appear. When Dark Gaia gets sufﬁciently peeved at Sonic’s constant attempts to blind him, he’ll pull out all the stops and attack with all six claws simultaneously. Quickly move to the screen’s center to avoid the attack. After the player destroy a number of Dark Gaia’s eyes, he’ll ﬁre projectiles of energy at you. Follow the onscreen button press at just the right moment to deflect the shot back at the source. The energy will temporarily stun Dark Gaia, allowing the player to collect rings and target his remaining eyes. Once the player destroy all six eyes, Dark Gaia reveals a seventh, much larger eye. Fly to the screen’s edge until the eye is directly in front of the player. If you have enough rings, the player prompted to make one ﬁnal Boost to put Dark Gaia down for good. The player must be aware that the rocks come ﬂying at Sonic faster than ever, and the player must have fast reﬂexes to dodge them all. Try to anticipate their trajectory and maneuver accordingly. When the player strike the eye, Dark Gaia is ﬁnally banished.

The time needed to S-Rank Dark Gaia is 7:30, total. Anything less gives a C-rank.

360/PS3 Version
This battle is more cinematic than the other version. Unlike other final boss battles in the Sonic series, Super Sonic is given a life gauge instead of a ring counter, which is increased when gathering rings and depletes when Super Sonic is hit by floating rocks or Perfect Dark Gaia's attacks. If Super Sonic's life gauge is emptied, the player will lose a life. In this fight, the player primarily controls Super Sonic, while playing as the Gaia Colossus during one quick time event.

In the beginning of the fight, Perfect Dark Gaia sets up an enormous shield that Super Sonic can't break. Super Sonic and Chip (in his Gaia Colossus form) begin by advancing toward Perfect Dark Gaia, dodging the rocks and energy orbs. It is also important for the player to gather up as many rings as possible with the boost to increase Sonic's life gauge, as there will be no other rings available after reaching Perfect Dark Gaia. After dodging the rocks, Super Sonic and the Gaia Colossus will reach the borders of the shield. Chip goes through the shield and distracts Perfect Dark Gaia, while Super Sonic goes and destroys the source of the power for the shield, which appear in the form of serpent heads that extend outside the force field. These serpent heads can be destroyed by making Super Sonic boost into them repeatedly, but the player must watch out for nearby rocks, which will cause the player to take damage if he/she don't avoid them. Chip has a life gauge as well, so the player must destroy the shield before Chip's life gauge is gone or he/she lose a life. Sometimes, Chip goes down and Perfect Dark Gaia starts to attack Super Sonic through the force field while the player tries to destroy the shield. It mainly attacks by shooting a large laser or calling several large rocks from the magma and throwing them at Super Sonic. Chip will eventually rise at some point and will try to distract Perfect Dark Gaia again, allowing the player to focus on destroying the shield again.

Once the shield is down, Perfect Dark Gaia grabs Chip with its six arms and starts to fire its laser to destroy Chip. Super Sonic goes out to save Chip by boosting into all six arms, which is done in gameplay by completing a quick time event (in the order of, , , , , /, , , , , ), where Super Sonic has to land one hit on each of Dark Gaia's arms. After that, Chip is freed and leaves Perfect Dark Gaia in agony, but it still had enough energy to shoot its laser at Chip. Chip takes heavy damage from the laser, but withstands and manages to negate it (by pressing / sixty times within ten seconds). Once Chip negates it, he punches and directly hits Perfect Dark Gaia. Super Sonic then comes and finishes off Perfect Dark Gaia by flying through its middle eye. The level immediately ends after that.

Videos
PS2/Wii = 360/PS3 =

Trivia

 * Perfect Dark Gaia is one of the two characters with the "perfect" prefix in their names, the other being Perfect Chaos. Both of these characters are final bosses.
 * In Sonic Colors, at the beginning of Act 6 of Asteroid Coaster, it looks like the roller coaster is coming out of a rock or planet that is shaped like Perfect Dark Gaia's head.
 * At the beginning of the 360/PS3 version, the fight against Perfect Dark Gaia is similar to Sonic & Knuckles '  Doomsday Zone (Avoiding asteroids and collecting rings). However in this game, crushing to asteroid takes a small part of Super Sonic's energy bar, while in Sonic & Knuckles, it only stuns him for a few seconds.
 * Perfect Dark Gaia bears a striking similarity to the God of Darkness from The Chronicles of Inotia: Children of Carnia. Both have a similar physical appearance, both draw strength from negativity and Chaos in humanity, and both seek to destroy the world.
 * The lava during the boss fight is noticeably brighter in-game, while in the cutscenes it seems to be darker and gives off less light.
 * In the Wii/PS2 version of the game, Perfect Dark Gaia's eyes are shown to have vibrant green eyelids, which close one at a time whenever one of the eyes is attacked. The eyelid on the central eye however, will not open until the other six are attacked. It is also worth noting that these eyelids are not visible in cutscenes.
 * Perfect Dark Gaia's in-game render shows him to have a slightly thinner head and larger eyes than his model in the CGI cutscenes.
 * If one looks closely during the shot where only Perfect Dark Gaia's head is visible above the lava, they will see that his central eye appears to be burnt off.
 * Looking closely right after Dark Gaia transforms, one will notice that only his central eye is staring at the Gaia Colossus while the others are all facing in different directions. This is also seen during the fight in the Wii/PS2 version of the game, in which the individual eyes can be seen shifting around and never looking directly at Sonic as he approaches them.