- Alternative Character Interpretation: On the one hand, the Doctor wants Barbara to know that the consequences of altering history will be with her forever. On the other hand, he knows that her actions will assuredly attract the Time Lords' attention. And it will be a most unhappy reunion, one that he'd rather avoid until there's no other way out.
- Harsher in Hindsight: Barbara's attempted interference in "The Aztecs" is made more dangerous by "Father's Day"; Tlotoxl was Right for the Wrong Reasons about there being cataclysmic consequences to heeding her.
- Love to Hate: Tlotoxl. Director John Crockett told John Ringham to "make all the children in the country hate you", but he was such a Large Ham, that Tlotoxl becomes a highlight as the serial's antagonist. It helps that he is one of the few villains in the franchise to completely win by the serial's end.
- The Woobie: Autloch. He has had serious qualms about Human Sacrifice as long as he's lived, but the other priests view it as vital. Then a Rule 63 reincarnation of Yetaxa shows up and vindicates himno, Tlotoxl has unmasked her as a fake.
YMMV / Doctor Who S1 E6 "The Aztecs"