YMMV / Doctor Who S23 E4 "The Ultimate Foe"

• Epileptic Trees: The cryptic information from the Master that the Valeyard is born between the Doctor's twelfth and final incarnations seemed clear cut at the time it was revealed, because this was back when the Thirteenth Doctor was considered the end of the line. Then comes the new series, which introduces an Odd Name Out that completely throws the numbering off (the War Doctor), an aborted regeneration that created a clone of the Doctor (the Metacrisis Tenth Doctor from "Journey's End"), and an expansion pack to the regeneration cycle - and suddenly it becomes much harder to understand this once simple statement. And then it becomes even worse in the Chris Chibnall era, when it's revealed that the Doctor actually lived an uncountable number of lives as the Timeless Child, long before the First Doctor came about. Or, y'know, maybe the Master was lying.
• Esoteric Happy Ending: Peri's body becomes the host to Kiv's brain before King Yrcanos supposedly finishes her. However, it is revealed later in this final episode that Peri in fact did not die and actually went on to rule Krontep alongside Yrcanos as his queen. While this is portrayed as a good thing, it should be noted that Peri showed no interest in Yrcanos the entire story and objected to the notion of becoming his wife, even if it arguably does beat being stuck on Thoros Beta with the Mentors. Expanded material has offered different versions of what become of Peri, though actress Nicola Bryant prefers her original fate.
• Fan-Preferred Cut Content: Some fans prefer Robert Holmes and Eric Saward's more ambitious script where the Valeyard is revealed to be the Doctor's final incarnation and really a frail old man who wants to steal the Doctor's remaining regenerations to stave off death. It would have ended with the two of them struggling and falling down an abyss reminiscent of Sherlock Holmes and Professor Moriarty in "The Final Problem".
• Harsher in Hindsight: The Doctor's rant about how ten million years of civilisation has made the Time Lords corrupt becomes this now that it's been revealed in "The Timeless Children" that the civilisation was built on torture and experimentation of a child (and said child became the Doctor themselves, but no longer remembers it). As that episode would render the Doctor as the Monster Progenitor of the Time Lord race, his rant retroactively comes across as being like a parent expressing his disappointment at their child's actions.
• Hilarious in Hindsight:
  • The Doctor battles his evil counterpart in The Matrix, well before Neo took the red pill.
  • The Sixth Doctor's last words spoken onscreen are "Carrot juice, carrot juice, carrot juice!". Just replace "carrot" with "beetle" and… well, you get the idea.
• Retroactive Recognition: Popplewell is played by Geoffrey Hughes, who would later be best known for playing Onslow in Keeping Up Appearances and Twiggy in The Royle Family.

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