Cyber-Controller (Supremacy of the Cybermen)

In an alternate timeline, a Cyber-Controller ruled an asteroid colony of Cybermen at the end of the universe. Following the arrival of Rassilon, it kept its existence hidden from the Time Lord, allowing him to believe he commanded the Cybermen in their total conquest of time and space. Eventually, it revealed itself to the Twelfth Doctor after the Cybermen attempted to harvest his regenerative energy, and revealed its plans to rebirth N-Space as the "Age of the Cyberiad". (COMIC: Supremacy of the Cybermen)

Biography
This Cyber-Controller ruled a remnant force of Cybermen that existed at the end of the universe. When Rassilon, sometime after being exiled from Gallifrey by the Twelfth Doctor, landed his bowship at the Cybermen's asteroid colony, the Cyber-Controller kept its presence unknown to Rassilon as he consulted the Cyber-Leader over his plan to make the Cybermen the dominant species across all of time and space. After Rassilon was converted into the Cyber-President, he assisted the Cybermen in forging the Gallifreyan Cyber Fleet to invade Gallifrey, with a particular focus on the Capitol. While the Cybermen made use of Time Lord technology to gain complete dominance over the past, the Cyber-Controller allowed Rassilon to believe he was in charge until the final stages of the Cybermen's plan were ready to be enacted.

After Rassilon, the Twelfth Doctor and the General arrived at the chamber of the Eye of Harmony, the Cybermen eventually forced all three Time Lords into looms to harvest their regenerative energy. However, the Cyber-Controller then intervened with a new strategy, explaining to the Doctor that the Cybermen intended to ignite the regenerative energy inside the Eye of Harmony at the exact moment the universe would end, rebirthing N-Space as the "Age of the Cyberiad", a reality which would be dominated by an ultimate evolution of Cybermen from its very beginning. Noting that Rassilon's regenerative energy readings were too unstable to complete the Cybermen's plan, the Cyber-Controller ordered the Doctor plugged in as a substitute, the two Time Lords eventually being upgraded.

As the universe began to rapidly collapse, the Cyber-Controller ordered the activation of the Eye of Harmony to create the Cybermen's ultimate reality. However, the stored regenerative energy began flowing backwards. It was then that the Doctor and Rassilon revealed that, despite their conversions, they had retained their consciousnesses and had altered the Eye of Harmony's protocols from within the Cyberiad. With regenerative energy flowing throughout the Cyberiad - which now spanned the whole of history - the Cybermen's conquest of time and space was reversed. The Cyber-Controller, who was directly exposed to the Eye of Harmony, was engulfed in regenerative energy as it screamed in despair, shortly before the timeline reset. (COMIC: Supremacy of the Cybermen)

Appearance
Unlike its subordinate Cybermen, this Cyber-Controller did not resemble the Cybermen that evolved from the Cyber Legions and formed the Cyberiad, (PROSE: Ghost in the Machine, TV: Nightmare in Silver) although, like most Cyber-Controllers, its brain was visible through a glass covering on its helmet. (COMIC: Supremacy of the Cybermen) The Cyber-Controller, in a similar vein to the Cyber-Controller on Telos in the 25th century of the original timeline, (TV: The Tomb of the Cybermen) lacked side handles on its helmet (possessing a pair of large blank, metal panels where a human's ears would normally be), a chest unit, or any other kind of external bodily components or mechanisms, aside from a thin, vertical oval-shaped electric white light on its chest. Its body was also significantly more muscular than most Cybermen, although not as much as the Cybermen of the Cyber-Earth in this timeline. The Cyber-Controller's face featured bright, white eyes with blue highlights, and lacked the "tear-drop" on the corners that were commonly seen on other Cybermen. Its face also featured a mouth slit.

Notably, this Cyber-Controller's appearance was nearly identical to the ultimate evolution that it envisioned the Cybermen achieving upon creating the "Age of the Cyberiad". However, this Cyberman design lacked the Cyber-Controller's chest light, brain case, or even a traditional Cyber-helmet with side handles; its face also lacked any kind of traditional Cyberman equivalent to a mouth. (COMIC: Supremacy of the Cybermen)