Nu Who Meta: companions and challenges
In the Russell T. Davies era, each companion faced (and had to work up to) a specific challenge: Rose became Bad Wolf, Martha had to walk the earth powered only by faith, and Donna became the Doctor!Donna. Do you think these challenges were specific to these characters, or do you think other companions would have been able to fulfill them (e.g. do you think Amy or Donna could have become Bad Wolf, do you think Rose or Rory could have become Doctor!Rose or Doctor!Rory, etc)?
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