Most played cards in Grixis Death:

1 Decks
Thoughtseize
4 copies - 4 average
Thought Scour
4 copies - 4 average
Mishra's Bauble
4 copies - 4 average
Death's Shadow
4 copies - 4 average
Stubborn Denial
4 copies - 4 average
Bloodstained Mire
4 copies - 4 average
Polluted Delta
4 copies - 4 average
Gurmag Angler
4 copies - 4 average
Street Wraith
4 copies - 4 average
Fatal Push
3 copies - 3 average
Kolaghan's Command
3 copies - 3 average
Scalding Tarn
3 copies - 3 average
Snapcaster Mage
3 copies - 3 average
Inquisition of Kozilek
2 copies - 2 average
Collective Brutality
2 copies - 2 average
Disdainful Stroke
2 copies - 2 average
Surgical Extraction
2 copies - 2 average
Plague Engineer
2 copies - 2 average
Ceremonious Rejection
2 copies - 2 average
Dismember
2 copies - 2 average