Anyway, if this synopsis is even half true, it would be a trully terrible exit bow for RTD, and an even worse curtain (post-curtain?) for the Fifteenth Doctor era. If I were RTD, I'd bring back Ncuti for the Christmas special, as a Doctor whose regeneration is "failing" and keeps regenerating briefly as his past companions (goes back and forth between Rose and whoever else can cameo for a day's work) before returning always to his look as the Fifteenth, and tries to work that out as he resolves whatever Christmas episode obstacles are on his way, regenerating fully well at the end of it.