Infinite

Infinite (インフィニット Infinitto?), also known as the "ultimate mercenary" (究極傭兵 Kyūkyoku Yōhei?), is an antagonist that appears in the Sonic the Hedgehog series. He is a jackal, and the former captain of the Jackal Squad mercenary group. During a raid, Infinite was hired by Dr. Eggman to become the leader of the Eggman Army, only for him and his squad to fall at the hands of Shadow the Hedgehog while protecting one of Eggman's facilities. Ashamed of his loss, Infinite decided to obtain the power of the Phantom Ruby not only as a means of becoming stronger, but also to abandon his "weak" past self.

With his newfound power, Infinite aided Eggman by helping him expand the Eggman Empire to its largest size to date after defeating Sonic the Hedgehog. Near the end of the war with the Resistance though, Infinite would engage Sonic and the Avatar on multiple occasions until he was defeated during the decisive battle for the planet.

Concept and creation
During the original drafts, Infinite was originally called "Zero". His final name ("Infinite") was intended to reference the nature of his ability.

According to the producer of Sonic Forces, Shun Nakamura, Infinite was created with an impressive and strong presence in mind since he would be accompanied by old bosses in Sonic Forces. This is the reason why he was made stronger and faster than Sonic the Hedgehog. His nature likewise inspired the staff to elaborate on his origin story. Sonic Team was also peculiar about giving him a cool, but evil design, with his mask being designed especially to emphasize his evil nature. Character artist Shinkichi Tanahashi later elaborated that Infinite was designed as a vicious existence that stood in the way of the bonds with friends that Sonic represents. His overall design motif was derived from the Namahage, a demon-like being in Japanese folklore, with focus on key words like "cruel", "clinging to power", and "not believing in bonds." Since Namahages look scary, they also made for a cool and catchy silhouette that Infinite came to possess. Tanahashi noted as well that the design process was difficult, but that the silhouette of Infinite's face logo worked well during development.

Infinite went through several design changes. His original design was that of a ghost-like figure, with one of the examples including one with monster-like horns. A common element his early design shared with his final one was his mask and large hands with sharp claws. The team later proposed a design using a buffalo motif, but it got scrapped in favor of his current jackal motif, which would settle as the outline for the character's design. Infinite's species in particular, the jackal, was derived from Anubis, the ancient Egyptian god of the afterlife, who possesses a jackal head. These designs included bandages to create an eerie sense of coolness. It was also around this time that Infinite's mask began to take on its current form, albeit with scars on it. This mask was given its patterns inside the ears (with one pattern on one side and the inverted colors on the other) because it gave it a geometric eeriness. Late in Infinite's design process however, it was decided that his bandages and the scars on his mask were to be removed because they made him "look weak." Following then an adjustment in colors, Infinite reached his current design.

Appearance
Infinite is an mobian jackal with black fur. He has a white fur pattern on his back that resembles a ribcage, a bushy tail with five white tips, and long, white, stiff dreadlocks. His muzzle is white and protrouding with cheek tufts, and he has a black nose and noticeable fangs. He has complete heterochromia, with his right eye being blue and his left eye being yellow. There is a large white scar across the right eye. He wears a white collar around his neck and black gloves with silver designs on the backs, covering his sharp claws. He also wears pointed, metal and black hi-tops, with his personal infinity symbol engraved on the red soles.

After abandoning his old identity, Infinite began wearing a silver-colored mask with white and black circular patterns on the inside of the ears, with the right ear being black with white circular patterns and the left being white with black circular patterns. While his left eye is visible through a red visor, his right eye is covered by a black lightning bolt-shaped piece, similar to an eyepatch, that is connected to his mask's right ear, which glows red when he uses his power.

Infinite possesses the finalized version of the Phantom Ruby copies that is fused to his chest. When Infinite channels the power of the gemstone, he can surround himself in a red aura, with red, glitch-like pixel particles scattered throughout his body.

Trivia

 * According to Ian Flynn who asked what Infinite's real name was when writing the script for the Sonic Forces digital comic, Sega has stated that "Infinite" is in fact his real name.
 * It was also revealed by Flynn that Infinite, alongside the Jackal Squad, are not allowed to be used in the IDW Publishing Sonic the Hedgehog comic series.
 * People say that infinite could be majin sonic from that creepy sonic cd easter egg
 * Infinite is the second Sonic video game character to be depicted with heterochromia, with the first being the Commander.
 * Infinite has a brief cameo in the "Come Join the Eggman Empire" propaganda video nearing the end, where he emerges from behind the Egg Pawns when the narrator claims that the possibilities for those under his Empire are "infinite", acting as a subtle pun as well as a foreshadowing.
 * Infinite is the most frequently fought boss in Sonic Forces, fought a total of three times over the course of the game.
 * Infinite is the second villain which disparagingly refers to Sonic as a rat with Sonic correcting him regarding his actual species. The first is Erazor Djinn.
 * Concept artwork for the stage Null Space implied that Infinite would have been encountered in the level to some capacity.
 * Infinite's Phantom Ruby-induced aura varies in design depending on the medium. In the E3 2017 trailer and the comic prequels, his aura is depicted as being flame-like. In the Xbox One/PS4 versions of Sonic Forces, his aura glows red and forms a purple haze with various glitch effects. In the Switch version of the same game, he instead merely has a red outline.
 * Jokingly, according to Sonic Twitter Takeover 3, Infinite collects or at least has some form of media involving the popular romantic ship between Sonic and Shadow.
 * In two pieces of concept artwork, it is shown that Infinite could have used his tail as a "third arm". The reason this idea got scrapped is unknown.