1 Healing Cards. The healing cards are very powerful. The Elixer of life puts 12 non-healing cards back in your deck. It is a potions card and with all the common cauldrons out there I think you are going to see a lot of healing cards. So I think the obvious thing to do here is plan to play against this type of card. Use item removal to get rid of those pesky caludrons. (Cauldron to Sieve comes to mind here.) as well as the targeted card removal. One nice thing is that it is not normally possible to get a healing card back once it goes to discard. If you can drop your opponents best healing cards in the discard pile it is going to make for an easier time decking them.

2 Adventure cards. Not to sure how these are going to work out. At first glance they are very powerful in most cases. But looking a little deeper (in all of the hour I had to figure this out) I found that they may not be worth the cost. First off is that they cost both of your actions. Not sure I like that. Plus there are cards that can remove Adventures. One does it without reward and the other salavage the reward for you. (Draco's Something or other.)

3 Critters. Looks like the most straightforward way to win. Most of the more damaging creatures have a discard a lesson as part of the cost. So keep an eye out for lesson removal and get rid of the Care of Magical critters lessons whenever possible. Also a good idea is to wait till the critters with discard costs are out and then unsummon them. Most critters can no take a lot of damage either, so keep a few 1-3 direct damage spells handy.

4 Toad. I think this card is going to be huge. Right up there with the Invisibility cloak. Toad lets you redirect damage from you to it. That Steel Claws/Hagrid combo becomes less amazing when all it does it splatter a toad across the room. (Anyone have any Toads for trade?) The invis cloak is nice as well, but it is very expensive to cast. (11 or 12)

Thats all I can think of for now. I will try to send more as I start to playtest the ideas. I threw this together at work, feel free to correct any spelling errors or mistakes as you see fit.