MG will possess all of the usual powers that a vampire has. That means he's not going to be rendered the most powerful person in the world after a few episodes.
Jenny Boyd plays Lizzie Saltzman. At first glance, she has Caroline's signature blonde locks, but how will genetics work because the twins were, you know, transported into Caroline's body after Jo's death?
Alaric: Cheater! Hope: You should really get a vampire to start doing my training. You're getting a little old for me to break your human bones. Alaric: How dare you.