I don't see how nobody has said sediment shield is OP, either.
/Plays shield
/Chains sundials for 10 turns
/Shield now blocks 12 damage per creature
So, the only way to power down the shield is then to get a creature with over 12 attack, and then it only powers down by one. Sure, it could be able to be gotten around eventually, but by then any shriekers would have killed you 10 times over.
(Deck I would use: 6x dials, 4x shield, 6x graboid, 2x shrieker, 12x stone tower). Mark of time.