One of the most challenging rulesets is the combination of earthquake and poison. If you don't have the cards for it, you are looking at 4 damage each round for each of your monsters. That is brutal.
This is where Kralus comes in. It has both the immunity and flying abilities. Talk about being made for a ruleset. Just put him at the back to wait out your opponent's monsters all dying and then leave him to pick out the remaining weakened foes. Even Kron doesn't do as well as Kralus with this ruleset.
Now, today I had the sneak quest which allows for flexibility with my card choices. As you can see, that leads to some strange lineups like having the sandworm in front.
Looking forward to the season ending and the rewards already. It feels quicker than usual, though. I thought the previous season just ended.