Here's the zipfile containing all the cards, in the form of HTML documents you can print. This is all beta at the moment; there's no version number; it can change at any time. Here are the step by step instructions to get the cards into a playable state:
Download and extract the zipfile; preserving directory structure. You'll get something like this:
Navigate the directory structure and fine the 'card_X.html' file for the hero/villain/environment you're looking for. For example, 'card_skitter.html':
Open the file in your preferred web browser. You should see something like this:
Print the web page. Be careful with the margins in your printer settings, and you probably want to print in portrait, not landscape. You should be able to get 9 cards a page if you're printing on A4:
Cut the cards out. I use a guillotine because I can't cut straight; if you have better hand-eye coordination than me scissors will probably work.
Put each cut-out paper card front and a standard playing card in a card sleeve. Make sure the back of the playing card is the visible side or you'll be able to tell the cards apart from behind.