I remember reading these in the mid-to-late 80s, IIRC. I don’t remember the title, the character names, or the author.
The basic premise is that one of the main characters belongs to a secretive race or society of witches or sorceresses which is fleeing the world they’ve been on. This female main character somehow becomes separated from her people and basically stranded on that world. She meets up with a human warrior or knight who is determined to accompany and protect her until she finds her people, despite her protests (she considers him inferior for being a non-magical human or something like that).
I think in the second book, they find her people, but the society rejects her because she travelled with the human and came to fall in love with him.
The more I look at that series, Busy Scissors, the less I think that was it. I seem to remember the woman as being a younger member of her group, and eventually actually meeting up with that group (rather than being the sole survivor).
None of the online images of the covers look like the covers I remember, either. I don’t really have a vivid picture of the covers, but I can say that nothing I saw online rings any bells.
Probably Six of Swords by Carole Nelson Douglas. Mirror-eyed sorceress, can’t look into reflections herself, tears turn to gemstones. Warrior has a honkin’ big magical sword (one of six, 'natch). Floating island; worldwide catastrophe, etc. There was a magical cat in there, too, IIRC. Sequel Exiles of the Rynth and other ones that I’ve completely forgotten.
THAT’S IT! I had this very vague sense (so vague I didn’t put it in because I wasn’t sure if it was accurate) that cards were involved, and “Six of Swords” would explain that, plus I actually remember “Exiles of the Rynth” as a title.