You're right, apparently it was said that Isobel is a descendant of Katherine, somehow making Elena look just the same as Katherine. How bothersome.

I don't get it.
Will somebody please explain to me the logic behind the "doppleganger" nonsense? Why does Elena look identical to Katharine? They aren't even related.

How has this entire topic gone by without a mention of Badlaa? Shit, not even a mention of Underneath (an episode so bad that 1014 actually apologized for it)?

Caleb would have been so much more awesome if he appeared within the first 10 episodes of S7. That would have given time to establish an actual backstory for him, and maybe even show him attacking the Watchers' Council.