Most played cards in Marchesa, the Black Rose:

2 Decks
Dark Confidant
2 copies - 1 average
Baleful Strix
2 copies - 1 average
Dismember
2 copies - 1 average
Demonic Tutor
2 copies - 1 average
Toxic Deluge
2 copies - 1 average
Snapcaster Mage
2 copies - 1 average
True-Name Nemesis
2 copies - 1 average
Wooded Foothills
2 copies - 1 average
Temple of Deceit
2 copies - 1 average
Watery Grave
2 copies - 1 average
Verdant Catacombs
2 copies - 1 average
Vendilion Clique
2 copies - 1 average
Dig Through Time
2 copies - 1 average
Ulcerate
2 copies - 1 average
Lightning Bolt
2 copies - 1 average
Preordain
2 copies - 1 average
Liliana of the Veil
2 copies - 1 average
Bitterblossom
2 copies - 1 average
Dack Fayden
2 copies - 1 average
Jace, the Mind Sculptor
2 copies - 1 average