The Havens Event Kit includes new Havens cards, which will gain additional powers and abilities as they are used over multiple games. Havens are sanctuaries for druids in a world of spreading darkness, offering places where warriors can rest and recover. They are vital strongholds for the druids’ crusade. These new cards and their mechanics, are only available as part of the event kit.
The last expansion for the Mystic Vale card game released in July (see "'War Chest,' 'Expansions for 'Mystic Vale' and 'Smash Up'").