Board Thread:General Discussion/@comment-1962215-20140316231135/@comment-8345449-20140326152222

It was Cora's crypt that was blood locked though, not the castle itself. So therotically, she could have entered the castle through other means and then got into the crypt using Regina's blood.

But then one has to wonder why Zelena would go through all that trouble to claim a half-sister relation with Regina? And why the grudge with Regina if there was no such relation?

The other thing is how she managed to escape Regina's office in Storybrooke. So you have one drop of blood from the caster and all blood magic is useless after that?