As so many long-times fans have become furious with the direction of “Doctor Who” thanks to the current show-runner, Chris Chibnall, and the horrendous portrayal of the Doctor by Jodie Whittaker that the show has lost nearly all of its fan-base in the USA and other countries as well as in Britain.
However, the situation is not a dire as you might think and there are ways to “fix” the “dumpster fire” created by Chibnall and Whittaker. The following is my synopsis of one of several ways the show can be fixed utilizing established canon that would not seem “outlandish” or require any major retcon of the show.
At the end of “Twice Upon a Time” the 12th incarnation starts to regenerate, appears that the Doctor regenerates into a female Gallifreyan, and the “regenerated Doctor” is thrown from the TARDIS after a series of what appear to be “massive system failures”. While recovering on Earth this “regenerated Doctor” shows signs of “post regeneration amnesia” and is also forced to utilized a teleportation device to reach the TARDIS. These may not seem all that unusual for a recently regenerated Doctor, but it has already been established numerous times in Doctor Who that appearances can be deceiving.
In reality the “13th Doctor” is not the Doctor, but a bio-synthetic replacement being used by Rassilon in his effort to get revenge on the Doctor for being driven from Gallifrey after a military coupe led by the Doctor that resulted his exile from Gallifrey along with the High Council.
The coupe by the Time Lord military did not last long after the failed attempt by the Doctor to “save” Clara Oswald and the failure of the Doctor to return to help lead the Time Lords led to those who were still loyal to Rassilon gaining increasing support and the eventual return of Rassilon and the High Council to Gallifrey. Upon their return they began a plan to get revenge on the Doctor.
Their initial plan was to eliminate the Doctor by setting a trap for him utilizing the colony ship Mondas and two incarnations of the Master. It appeared to succeed and the Doctor was going to let himself die and not regenerate. Still wanting to know the secrets the Doctor was keeping about the Hybrid, Rassilon and the High Council engage the services of the Testimony Foundation to acquire that information as well as any other secrets the Doctor was keeping. The Testimony Foundation failed and Rassilon was forced to take more drastic measures.
Having already failed with the confession dial and then the Testimony Foundation, the decision was made to utilize a bio-synthetic “replacement”, based on a hybrid of Dalek infiltration agent and Human “Flesh” technology, that would impersonate the Doctor while the actual Doctor was kept in stasis on Gallifrey until Rassilon and the High Council could pry his secrets from him.
The Time Scoop was use to extract the 12th Doctor just moments before he began to regenerate and replace him with the bio-synthetic duplicate. Unbeknownst to the High Council, Rassilon made the duplicate female instead of male and created subtle alterations in the personality matrix as part of his plan to destroy the “legend” of the Doctor. To help hide this, Rassilon installed a link to both the Matrix and the Testimony Foundation archives to enable to duplicate to give the appearance it was the Doctor by being able to access the records on the Doctor stored in both locations while still acting on the programming Rassilon had embedded into it.
The plan seemed fool-proof, but the psychic bond between the TARDIS and the Doctor was underestimated as well as the interference the link to the Matrix and Testimony Foundation would cause to the Type 40 operating systems. After the transfer took place the TARDIS reacted violently to the impostor and the disruption to its systems caused by the link. The duplicate was ejected and the High Council quickly recalled the TARDIS to Gallifrey to correct this problem.
The duplicate suffered some minor damage upon landing on Earth and that mimicked “post regeneration amnesia” until the nanite self-repair system could fully repair the receiver and the link to the Matrix and Testimony Foundation could be reestablished.
With the receiver repaired and the issues with the TARDIS handled a signal was sent to the duplicate to build a teleportation device to reach the modified TARDIS.
Eventually the duplicate is exposed, the real Doctor is rescued and Rassilon and the High Council are defeated.
As you can see, this could all be used once Chris Chibnall leaves as show-runner and Jodie Whittaker wants out of the series with no impact on canon or produced work while reinstating the Doctor as the character he has always been.