Cassie & Diana could have a really good relationship together.. They are both good girls, and great witches.
The only problem in their relationship is Adam. Adam is in love with Cassie, and also with Diana! And Diana has been in love with him since always, and Cassie just came to town being Adams "destiny". So who should be with him? That the question, and there is going to be a fight over him. In 1x06 we saw that Diana was destroyed after breaking up with Adam, and than she came over to Cassie, and Cassie wasn't happy at all for it (or at least that's what was shown) and she hugged Diana :) It was sweet, but will this friendship, which just started really last?
I kinda like Dianas character more than Cassies.. And Diana is prettier then her :P But I like Cassie & Adam :)
Thoughts?