I wonder if Nicodemus had planned on getting the Eye, and that's what Skin Game was about. Either a trade, or using the Holy Relics to defeat Ethniu, and get the Eye for himself... Maybe the Eye could be used to break them from their Coin's or so he could kill someone? Lucifer did lock them in the Coins because they were most likely to betray him, maybe Nicodemus is planning just that.
He didn't get the Eye but he could be planning on blackmailing Dresden for it in the future.