I used the advice in this thread to win it (use a mage deck, and get yourself a "Book of Wizardry" quest card by beating Ethernaught Scenario 1... and a couple of Wayfarers Bread from Oathbreaker Scenario 3).
http://forums.station.sony.com/stra...?topic_id=17359
Took me a few tries before I got lucky with drawing the right cards at the right time.