This guy! The Crystalloid Tormentor!
He has the highest defense of a single card that I've found for 2 star cards. He is better than almost every 3 star defense cards with raw stats and almost as good as 4 star cards.
He is a reward for defeating the 3rd boss (you can always repeat killing bosses) and is quite easy to get multiples:
Level up 5 of these to 160 and you'll have over 48,000 defense. That'll show em! Let the free gold roll in!
