I read this as a teen so early 2000s, but our local library had a rather old collection of books, so I would guess it's 80s or 90s (if not earlier). It's a 3 part series if I remember correctly, where magic in the book causes a faint sweet smell of almonds (I think it was almonds). The protagonist cannot perform magic, he is a prince or some such and not particularly tough at the beginning of the story (possibly jealous of his brother?), goes on a journey, falls in love with a zombie woman, helps save the day and returns as a tougher and worldlier man.
Other distinctive plot elements I remember is that the woman he falls in love with was initially an assassin sent to kill him after she had her heart taken out of her body. I believe that in the end they also vanquish evil by joining their hands together.
I would love to find that book again, if anyone has a clue it'd be greatly appreciated!