So people tend to say that Scrying Pool is a good counter to Cultist and Marauder, since they flood your deck with Actions and Scrying Pool will draw through a bunch of Actions. But if that happens, then you end up with a hand full of Ruins, which is... not that much better than having a hand with no Ruins (unless you've got a really good surplus of villages), is it? And there are situations where Ruins can interfere with your Scrying Pool draw—if your decktop is Ruined Village and Copper, you'll scry and draw them; but if the Ruins aren't there, the Copper is on top and you might discard it and draw the goodies below. ...So it's not all that obvious to me that Scrying Pool counters Ruins as effectively as it sounds.