I thought Swift was easy. I farm him consistently trying to get the Raubahn card from him.

I've already defeated 30 of the 32 NPCs. Other 2 include Sezul, which my rep is too low still. I know max rep is not required, but rep has to be at a certain point. The other one is the Indolent Imperial, which I have yet to even try.

The hardest for me of the 30 I have played is Marcette and Rhutwyda of the Three Hearts. I beat Rhutwyda quite easily when I had very few cards and no deck upgrade, but then I went back to face her yesterday for a card I didn't have yet, and her deck was stronger and I hardly ever could defeat her. Her deck was stronger, with higher stars than any of those other 29 NPCs I had beaten, which was strange because when I first fought her with less cards she was easy. Made me wonder if some NPCs get stronger the stronger you get. Therefor I am unable to get Urianger from her, so decided I'll have no choice but to come back when I get my 60 card deck upgrade. I'm currently at 47.