But keep in mind that if a card has in its mana cost, the amount is treated as zero for the purposes of determining converted mana cost. So cards with only s in their mana costs are, you guessed it, cogs.
Here's a list of cards that you might have missed for your cog decks because of that .
Phyrexian Marauder - It's an artifact creature from Visions that you can make as big as you please.
Shifting Wall - This artifact wall from Stronghold can be a useful thing to tutor for when you're facing down a large attacker.
Engineered Explosives - Although you play it with lots of colors, its converted mana cost is still -- and it's a great way to rid yourself of problematic permanents.
Chalice of the Void - Remember, all s are treated as zero! So you can search up a Chalice when you know your opponent has spells of a certain cost that you want to stop.