Upgrades, False Gods, and a small amount of pestering
I'm going to take my life in my hands, and say stop all purchases of upgrades. Not upgrades themselves, no, just the ability to buy them. For level 0, no chance of getting upgrades from the spinners, and other AI levels have a small chance of getting one, either as a card, which you can play ingame like plate armor, so that you can choose which cards are upgraded depending on the circumstances, or just a randon card upgrade in your deck. PvP, upgrades are given depending on the proportion of upgraded cards in that deck.
As for the false gods, neuter them. Make them play by normal rules, but for two things:
HUGE health-perhaps even 1000HP.
New deck rules - when an FG runs out of cards, they do not lose. They do however, completley redraw, as if they had only just started to play so have 22-52 cards, and a hand of eight.
Also, people that have upgrades can keep them, so as not to waste their time and money, and people that have, say, less than 5 get two or three random upgrades, or as many as takes them to 5, just to get the ball rolling. New playes would get some too, to make it fair - say every starter deck has two random upgrades.
Also, I hate to pester, but what do people think of my DSiWare idea. (this was posted after reading page 57, so it may have been talked about already). It dosen't of course have to be nintendo, of course, just a non-flash game. I'm still contemplating a source version, but not much progress there, I'm afraid.