Imperator Pir'Oth Ix is leader of the titular organization in Sonic Chronicles: The Dark Brotherhood, and the game's main antagonist. A megalomaniacal albino echidna with a knack for techno-wizardry and Machiavellian politics, Ix orchestrates the capture of all seven Chaos Emeralds and the Master Emerald, in a scheme to break the Nocturnus Clan out of the Twilight Cage.
Ix has ruled the Nocturnus Clan echidnas "for as long as we can remember" (according to Shade in TDB: Chapter 6). Four thousand years ago, when the Nocturnus still lived on Sonic's world, it was Ix who incited the tribe to war against Knuckles' ancestors, the Knuckles Clan. Bloody warfare against Chief Pachacamac's warriors only ended when the Perfect Chaos cataclysm (recounted in Sonic Adventure) destroyed the Knuckles Clan, leaving Ix and the Nocturnus with no further obstacles on the road to complete conquest of the ancient world.
However, the Nocturnus Clan itself fell victim to supernatural catastrophe: the Argus Event. Without warning or explanation, the entire civilization was uprooted from Sonic's world and cast into the Twilight Cage; a slow-time prison-dimension occupied by a host of fearsome alien races. Forced to adapt or die, Ix continued to lead the Nocturnus in the Cage's nightmare environs, brokering strategic alliances and pitting his enemies against one another, as the Nocturnus society evolved from an ancient-era tribal civilization to a sinister technological empire. The echidnas were eventually able to subjugate or pacify their Caged opponents, and turned their attentions to escape.
At the start of Sonic Chronicles, Ix dispatches Procurator Shade back to Sonic's world using warp belt technology developed by the Nocturnus inside the Cage. The Imperator himself later comes to Angel Island, to personally capture the Master Emerald. After fighting Sonic and Knuckles to a standstill (and declaring Shade an insubordinate traitor), Ix uses the Master Emerald to open a wormhole, and retreats to the Twilight Cage to prepare his invasion.
During the second half of the game, Sonic pursues Ix into the Cage and marshals the other imprisoned races against the Nocturnus. After the heroes fight their way to the throne room of the Nocturne citadel, Ix attempts to convince Knuckles to side with the echidnas - but to no avail. After fighting three consecutive battles, of which he has a total of 1600 HP in, the most of any other enemy in the game (aside from Super Ix), the Imperator remains unbroken. He uses either the Chaos Emeralds or the Master Emerald (the game is unclear on this point) to transform into the final boss, Super Ix. But after being defeated by Super Sonic, Ix still won't go down; he teleports away as the Nocturne begins to fall apart. His eventual fate after The Dark Brotherhood is unknown.
- Although it is never mentioned in Sonic Chronicles: The Dark Brotherhood, Ix's first name, "Pir'Oth", is given in the title of his character information box on the game's official website; see screenshot or original source.
- Ix's design is reminiscent of two other white-furred, technophilic echidnas from alternative Sonic continuities: Doctor Finitevus, from the Archie comics, and Doctor Zachary, from Fleetway's Sonic the Comic.