The dagger didn't work the 2nd time because Davina didn't dip it in white oak ash. She simply put it back but that's useless. That's why Elijah said removing the dagger even once would negate its power because it would need the white oak ash again.
Cami - one of the most well-conceived characters in the series, and played by Leah Pipes in the best possible way. And of course, the chemistry between her and Joseph Morgan is simply amazing;even since their first meeting in The Vampire Diaries.
That Klaus and Cami moment is one of the reasons why I love originals so much. The acting in the show is much better but I think it's because there is already so much history we have with the main characters and also because it's more grown compared to Vampire diaries which I still enjoyed.
If I remember correctly there are different kind of witches. Some use the nature and some use the power of their dead family. They got a connection to the other side and multiply their power by the power of their ancestors. The cemetty and the place in TVD where the witch massacre happened can be such places.
You ever got see this side of Klaud in TVD cause there everyone were children , yes including Caroline Camille is very mature and brazen, she is like a mature Caroline who is not afraid to speak her mind to Klaus, and klaus likes strong people like that....... Klaus does not want Cami to pursue her interests cause he wants her to focus but if you see it other way than Klaus has seen people on a mission and they dont end up well, so he protects her....... Very selfish, but very klaus like......Klaus does care, but he refuses to accept it
Klaus is doing what he must do for his family. He shows he has enough heart to not just say forget your brother. He tries to be kind and even offers to solve this. I mean honestly inst that a dream deal. Hey ill make you forget the worst thing in your life and when i solve it ill give you back the memories. That or feel empty and have night terrors for possibly ever...
So if I remember correctly, there are different types of magic that witches can practice like sacrificial, voodoo, expression… Most witches in New Orleans practice ancestral magic which means that they are tied to certain place to practice it. There are different clans of witches in New Orleans- currently the focus is on witches of French Quarter (I think it’s the name of the place where they practice and also the name of their coven) since Marcel has forbidden usage of magic there (because Davina can sense it, since she is/was a part of that coven).