I am soon going to start a new project just for the lulz that is a HoN card game. I am imagining it this way:
So you can have up to 7 hero cards in your deck. At the beginning of the game, your enemy must choose 2 heroes who he can ban and put out of the game.
Then, you set down all your hero cards into the front stage. They will be able to attack, and after each round you can draw 2 cards. Those are then spells or items that you can use. Items can be used through gold, and you have 100 gold through the match. You can of course increase this with items like Alchemists bones, which requires gold to use, but gives the player a little gold every turn. Items like nullstone will negate one incoming stun, but will still take the damage of the spell.