Here are official posters showing some interesting card/character combinations. I can only imagine the spells are meant to compliment each characters abilities and strengths. I wonder if the other characters suggested at the bottom of each poster also benefit from the propositioned cards some way.
I will have to look at the suggestions more closely myself: I wonder if they resemble the deck types I have already been pursuing. (Health Deak, Damage Deck, etc.) My decks were formed with overall objective being the unifying idea. I like the focus here being complimenting the characters themselves.
Post up if you try any...