Freyda is the Countess of the Unicorn Duchy and daughter of Godric, Commander of the Griffin Armies. A proud and capable warrior with a sharp tongue, she plays a big part in the war against the Demons and the defeat of Kha-Beleth's lieutenant, Biara. Later, she becomes ruler of the Unicorn Empire, alongside her not-so-suitable husband, Duncan Stag.
While I'm sure I have a reputation for always voting for the Paris actors, I have to say, not this time. Christina isn't bad by any means, but she doesn't get a lot to work with (as the character wasn't as well defined then), and makes her sound like a flighty young girl rather than a battle-hardened warrior. I'm sure she could've done a lot better with the revised version if the expansions had remained in Paris.
Cornelia, however, gets a lot more to work with (two expansion packs' worth), and manages to bring out Freyda's snarky side as well as her warrior side. While her acting isn't perfect, she manages to flesh out the character a lot more than Christina. Therefore, my vote's on her.