I have been playing Magic the Gathering Online to get ideas on game mechanics for RPG card games. I have played Pokemon cards several years ago with my kids. My game design is more similar to Pokemon - you only play one character card at a time.
One thing that I find interesting in MTG is that you are doing damage directly to the opposing wizard. Any damage from attack points that are not blocked by your character cards is applied directly to you, the player. This is different from Pokemon, where damage is only applied to the character card until it is removed. Three character cards that are "incapacitated" and you lose the game.