Nice to see so many Beatrix posts. She's so good.
Fighting her a few times in very moody, impossible to win battles really sets her up as this powerful entity. Once you come down to use her, it feels really earned considering her and the plot's development. Alexandria (and the state is in), her chemistry with Steiner and "Something to Protect" being such a motivating take on "Roses of May" (her theme) makes this one of the most memorable parts of any FF.
They should have made her playable for the rest of the game :(