Cyber-Planner (Alit in Underland)

A Cyber-Planner was the overall leader of the Cybermen created on Floor 1056 of a Mondasian colony ship, after lost control of the Cybermen due to the efforts of the Twelfth Doctor. (PROSE: Alit in Underland)

Whilst the Cybermen spent centuries evolving themselves into more advanced forms, (TV: The Doctor Falls) the Cyber-Planner observed that the Cybermen's programmed definition of humanity had been altered. (PROSE: Alit in Underland) Unaware that the change had been made by the Doctor, (TV: The Doctor Falls) the Cyber-Planner ordered a patrol of CyberNeomorphs, led by a Cyber-Leader and a Cyber-Lieutenant, to travel to Floor 0508 to capture the Master and Missy so that the Cyber-Planner could interrogate the duo and learn of how the change to the Cybermen's definition of humanity had been made, as well as who had made the change and their intent in doing so. The Cyber-Planner also gave the Cyber-patrol secondary orders to unleash a swarm of Cybermats to attack Floor 0507, so as to weaken its human population in preparation for a future invasion. (PROSE: Alit in Underland)

Behind the scenes
Although no stories explain this Cyber-Planner's ultimate fate, it is likely that it served as the leader of the Cybermen during their attack on Floor 0507 in TV: The Doctor Falls, given the episode's lack of any sort of leadership Cyberman such as a Cyber-Leader or Cyber-Controller, and may have continued to serve as leader of the surviving Cybermen following the destruction of Floor 0507 and during the Cybermen's subsequent attacks on Floor 0502, as mentioned by Nardole in PROSE: Twice Upon a Time. The Cybermat attacks that Nardole mentions as continuing to occur every spring on Floor 0502 may have been led by this Cyber-Planner; if so, this suggests that this Cyber-Planner outlived the Cybermen by potentially millions, if not billions, of years, given the extreme time dilation between the floors of the Mondasian colony ship.