When we look at the roles that the Final Five have taken they help the colonial's in their quest for Earth, a parallel can be drawn between the Final Five and the five Wizards sent to guide men and elves.
Tori like Saruman has turned her back on her duty to help humans; instead Tori much as Saruman has started her quest for power.
There is a similarity between the death of Kara and that of Gandalf. Because Gandalf had willingly sacrificed himself and in so doing had placed his fate in the hands of a higher power, Eru (or Ilúvatar being that created middle Earth) sent him back to Middle-earth to complete his task. He became Gandalf the White, greater in wisdom and power. Kara whilst speaking with the being that looked like Leoben (remember he never said he was Leoben) in effect turned herself over to a higher power there by sacrificing herself. Now when Kara returned in the new Viper telling Lee that everything would be alright and she would lead them to earth I did get a bit of a twinge Gandalf saying “I am Gandalf the White. And I come back to you now - at the turn of the tide.”