Most played cards in Grixis Shadow:

1 Decks
Serum Visions
4 copies - 4 average
Fatal Push
4 copies - 4 average
Street Wraith
4 copies - 4 average
Thought Scour
4 copies - 4 average
Thoughtseize
4 copies - 4 average
Death's Shadow
4 copies - 4 average
Snapcaster Mage
4 copies - 4 average
Bloodstained Mire
4 copies - 4 average
Scalding Tarn
4 copies - 4 average
Polluted Delta
4 copies - 4 average
Stubborn Denial
3 copies - 3 average
Terminate
2 copies - 2 average
Watery Grave
2 copies - 2 average
Surgical Extraction
2 copies - 2 average
Anger of the Gods
2 copies - 2 average
Ceremonious Rejection
2 copies - 2 average
Inquisition of Kozilek
2 copies - 2 average
Tasigur, the Golden Fang
2 copies - 2 average
Kolaghan's Command
2 copies - 2 average
Gurmag Angler
2 copies - 2 average