I use the Zero cards whenever DR uses a sleight, but I still can't get any attacks in. The ZC's aren't arranged at the back, they're in three separate and hard to reach places. Three of them. I have to reload my deck as soon as I've used the last one and I can't get away from Riku.
I hate the dialogue! Games with lots of dialogue to skip have always frustrated me. They should've had a scene-skip feature.