Wow, this sounds really lame. I was going to try it out at some point, but I was thinking/hoping it was the more recent online version of Magic. (Isn't there an online version you can buy digital booster packs for, get some of the most recent cards, and build whatever kind of deck you want? Maybe that was just some weird dream I had.)
The old PC version of Magic with rpg-ish elements (basically it had a world map) was awesome. You actually got to play a traveling planeswalker/wizard or whatever. The most fun I've ever had in the card game was drafting decks from the Ravnica set. That was awesome -- if they'd somehow built the game around drafting and the fun of having to improvise a deck with what you get from a few packs, that would be awesome. But this themed-deck stuff sounds like it might as well be a different game.
