Thank you very much!
I haven't received other reports about Kitsune but there's room for improvement when it comes to balance, without a doubt. I'll keep that in mind and take another look at her!
Kitsune does have a resistance to purple spells. There is a "Resist" graphic that shows when using a purple spell on her, but I have yet to add special SFX for resistances and weaknesses so this might have played a role.
I also recommend using Witch cards as they're a small quick free heal and can give you some new options! Vuu's Veomea is also very powerful and great against Shapes ^^
If you don't have combo spells equipped, I'd recommend using at least one if you've got any in your inventory.