work in a group with others to transfer your excess cards from daily quests and they will send you cards to complete levels, do not combine cards till it's a level up, that way you can trade for them.
Important to have melee sneak monsters, and thorns vs. retailiate on small low mana if having to use in last position to fight against sneaks!, that way slow monsters have virtually 2 attacks....And melees
I received the Lord's prize, and then improved it to level 2. And the whole tactic is 3 dollars!