I have a few comments/questions.

4 flagstones for 4 plains? I would think you have too few plains for 4 flagstones to be worthwhile. I personally run 3 flagstones 5 plains.

Running humility and magus: This seems like an odd mix. Humility tries to punish creatures for their abilities. Magus has an ability that punishes players for playing numerous creatures. Humility makes magus worthless. I run humility but use Elspeth as a win condition as it feeds stax and is good with humility out. (not as good with ghostly prison I know) I would think you would be running O-Ring main instead of humility to deal with annoying things.