"Her?"
Casandra was ready to stride away when Max called her out and asked her to take Erza with her.
This stopped her in her tracks, turning around giving him a confused look.
If it was not clear, she only hated 2 two from the bottom of her heart.
First is Serena for the way she is rejecting her boss, and how she does not care about the way he expresses his love.
She still remembers she was asked to decorate the whole park like a new bride by him for his date with her.
But that woman did not even show up, she saw first hand how devastated he was when Serena rejected it to come.
Yeah she ripe benefits from Max spending the whole day with her, in that romantic park, for her it was their first date.
Still it did not stop her from hating Serena as no matter how much she likes to be with Max, his happiness is more important than her selfish desire.
As for Second Erza? She just hates her to be her replacement.