Silver's primary ability is psycokinesis which is also known as telekinesis. He is able to levitate objects (including himself) and use them as projectiles, and fly. He can also fire shock waves that temporarily paralyze his enemies. He is able to use many standard abilities similar to those of Sonic and Shadow and he can utilize Chaos Control in order to warp through time and space. He is able to transform into "Super Silver" by using the power of the Chaos Emeralds. His eyes turn red, his fur becomes a white gold color, and he becomes able to use a special "Shield of Light" to draw in and throw any object within a large circular field.

Metal Sonic is a fictional character who is an evil identical robotic replica of Sonic The Hedgehogand is able to match Sonic's every move and even surpass his namesake speed.Being a robot, Metal Sonic has no gender; however, he is referred to as being male, since he is a robot based on a male character, as well as having seemingly masculine programming. At the climax of Sonic Heroes, Metal Sonic (in his Neo Metal Sonic form) sends a bolt of lightning to the sky which destroys a large section of Eggman's flagship, creating a powerful vortex. The vortex sucks up several of Eggman's robot parts, which Metal Sonic absorbs. He then transforms into a giant, robotic dragon-like form (something similar to a metallic Perfect Chaos) known as Metal Madness. Metal Madness resembled Metal Sonic slightly, with the same blue coloring and head spikes. It had two eyes, one on top of the other, its right hand converted into a flamethrower and its left could fire its fingers like missiles. It could also project its spines at enemies. The only spot where Metal Madness could be attacked was a spot on its torso, which changed color. If it was blue, speed could not attack it, if it was yellow, flight could not attack it, and if it was red, power could not attack it.

Team Rose, Team Chaotix and Team Dark fought Metal Madness, who then completed his transformation by sprouting a pair of wings, lengthening his claws and flying away into the sky. He had now become Metal Overlord. In addition to his other attacks, he could fire crystals, use Chaos Control to freeze time temporarily, and pick up Egg Fleet battleships to throw. He was quickly followed by Team Sonic, who used super transformation to pursue him. The heroes fought and defeated Metal Overlord, who tumbled down to the flagship, reverted back to Neo Metal Sonic and then reverted to his original form.

Eggman. His goal is to take over the world. Sonic must stop him.

Sonic's arch-rival. Considers himself the "Ultimate Life Form". Very destructive.

Thinks he can outrace Sonic. However, sonic is still faster.

Wave the Swallow is a purple anthropomorphic swallow, the Babylon Rogues' resident technical genius, and a bit of a trash-talker. She is 18 years old, 110 cm (3'7") tall, and weighs 20 to 25 kg (44 to 55 lbs). She's the daughter of the tech expert of the Rogues' previous generation, and her knowledge of Extreme Gear far surpasses that of Tails and Dr. Eggman. Because of this knowledge, she is brimming with self-confidence; and as a result she "gives advice understandable to herself but not to others". However, she still considers Tails and Eggman to be worthy mechanical opponents.

Although she looks on Jet The Hawk as an "unreliable younger brother" and can be quite stubborn, she follows his leadership.

In the EX World Grand Prix, she beats Amy Rose at Splash Canyon, but is knocked out of the tournament by Tails at Green Cave. Wave uses a Type-W airboard, which is specially designed to fly well, and the red jewel she wears around her neck is actually a small computer capable of playing back media files via holographic projection.

Wave is something of a voice of reason amongst the Rogues, often reminding Jet and Storm of their responsibilities. Wave has something of a rivalry with Tails, in which she scorns the way he made Sonic's Extreme Gear, calls him "Shorty" a number of times, and also "a twerp" in one of her mission reports, though this diminishes by the end of the game. She also has a strained relationship with Storm, with one such instance criticizing his skills on Extreme Gear. In a cutscene before Sky Road, she angers Knuckles by calling him a "Red Mutt".

Wave often refuses to admit when someone has talent, as noted in some of her mission reports. She either says that she will continue to deny a person's skill or flat-out denies that they have any skill at all. She also says in the opening of White Cave, that if she doesn't take charge, nothing will ever get done.

Dark Gaia is the main antagonist of Sonic Unleashed and a gargantuan monster (referred to by Prof. Pickle as a hyper energy organism), the representation of darkness, night and destruction, who was released from the center of the Earth by Dr. Eggman's Chaos Energy Cannon at the start of Sonic Unleashed. Eggman plans to use the power of the great beast in order to conquer the world and establish his Eggman Empire. It is what spawns the monsters that plague the world during the night stages of the game.

Dark Gaia's purpose is to gather energy while sleeping at the planet's core over millions of years, then destroy the world upon awakening for it to be rebuilt by Light Gaia, a process repeated since time began. Because Dark Gaia awoke prematurely when Eggman fired his beam, its pieces scattered throughout the world, and its influence affected people negatively. The only exceptions were Sonic The Hedgehog because his will was too strong, even in his Werehog Form and Light Gaia because he is Dark Gaia's opposite. The other four unaffected areAmy Rose, Professor Pickle, Dr. Eggman and Tails for unknown reasons.

Over the course of the game, Dr. Eggman devises a way to gather the pieces of Dark Gaia and reassemble them, giving him the power needed to finally build Eggman Land. After Sonic (in his Werehog form) defeats Dr. Eggman's Egg Dragoon, the reassembled Dark Gaia appears. Eggman orders it to attack Sonic, but Dark Gaia, not intending to follow his orders, swats him away (nearly mimicking how Perfect Chaos shot down Eggman's Egg Carrier 2 after he began attacking Station Square in Sonic Adventure). Dark Gaia then re-absorbs its lost power from Sonic, costing him his Werehog form (which appears to injure Sonic in the process), and completes itself, gaining three extra eyes. Chip battles Dark Gaia in a giant stone robot formed by the Gaia temples known as the Gaia Colossus while Sonic attacks his eyes. While they are doing this, Dark Gaia completely regains his lost power and matures, growing seven eyes, and four extra arms (the in the transformation sequence it is only shown growing two arms), becoming Perfect Dark Gaia. In the end, Super Sonic and Light Gaia defeat Dark Gaia's final form, and both Light and Dark Gaia are resealed within the still-regenerating planet.

Light Gaia is Chip's real name. Born at the beginning of time, Light Gaia is the opposite of Dark Gaia, and is the representation of light, day, and rebirth. He awoke when Dr. Eggman split the world apart with his beam. Due to the premature awakening, he lost his memories, but regained them when Sonic restored the sixth of the Chaos Emeralds.

His purpose is to put the world back together when Dark Gaia destroys it. Dark Gaia dwells within the Earth's core for eons, feeding on the negative feelings and energies of the Earth's denizens, and emerging when it was grown strong enough. It is Light Gaia's job to defeat Dark Gaia and return him to the Earth.

To defeat Dark Gaia, he creates the Gaia Colossus out of the seven Temples of Gaia. In the end, when the planet begins to piece itself back together, Chip throws the exhausted Sonic back up to the Earth's surface and allows himself to be resealed within the Earth along with Dark Gaia. When Sonic comes to, he sees Chip lying unconscious on the ground, similar to their meeting, but it turns out to be an illusion as he quickly disappears. However, his necklace remains on the ground. Sonic puts the necklace on as a bracelet as Chip assures him telepathically that he will never forget him, and that he will always be with Sonic, a part of the Earth he treads. Due to his sacrifice it is unknown if he will return in future Sonic games, though it is unlikely.