Most played cards in Sidisi, Undead Vizier:

2 Decks
Snow-Covered Swamp
28 copies - 14 average
Jet Medallion
2 copies - 1 average
Thought Vessel
2 copies - 1 average
Duress
2 copies - 1 average
Dismember
2 copies - 1 average
Dark Petition
2 copies - 1 average
Dark Ritual
2 copies - 1 average
Demonic Tutor
2 copies - 1 average
Leyline of the Void
2 copies - 1 average
Damnation
2 copies - 1 average
Languish
2 copies - 1 average
Thoughtseize
2 copies - 1 average
Liliana's Triumph
2 copies - 1 average
Inquisition of Kozilek
2 copies - 1 average
Innocent Blood
2 copies - 1 average
Toxic Deluge
2 copies - 1 average
Hymn to Tourach
2 copies - 1 average
Mind Stone
2 copies - 1 average
Collective Brutality
2 copies - 1 average
Everflowing Chalice
2 copies - 1 average