Doctor Who: Every Version Of The Doctor Explained
2. The Fourteenth Doctor (First Appearance: 2022)
The Fourteenth Doctor had the face of his Tenth incarnation, but this wasn't another Metacrisis situation.
Fourteen was reunited with Donna Noble, who still had repressed Time Lord energy within her after absorbing part of the Metacrisis. However, Donna was able to pass on some of this burden to her daughter, Rose, which prevented her from burning up.
With Donna safe and sound, her and Fourteen travelled together for a brief time. They arrived at the edge of creation, where the Doctor invoked superstition – an action that allowed myth and fantasy to flood the Doctor Who universe.
Ultimately, this Doctor was shot dead by the Toymaker. But rather than regenerating, the Fourteenth Doctor bi-generated, a myth that was made possible thanks to his earlier actions.
Bi-generation resulted in both the Fourteenth and Fifteenth Doctors existing simultaneously. Fifteen jetted off to see the universe, while Fourteen, weary from centuries of battle, retired with Donna and her family.
This was why the Tenth Doctor's face returned. It was a reminder that he needed to stop.