They're for making your own cards. Which was actually kind of fun if you were playing against somebody who used it fairly. Like my buddy made a 10 mana 10/10 with protection from creatures named "Turd"...he even put in flavor text about how it smelled so bad that other creatures wouldn't touch it or something. Anywho, it did have something to do with the championship decks and I think it came out around the same time as the "Unhinged" expansion, which might help explain its purpose.