Most played cards in Mardu:

3 Decks
Night's Whisper
11 copies - 3.67 average
Pyroblast
10 copies - 3.33 average
Prophetic Prism
8 copies - 2.67 average
Kor Skyfisher
8 copies - 2.67 average
Rakdos Carnarium
8 copies - 2.67 average
Ash Barrens
8 copies - 2.67 average
Lone Missionary
8 copies - 2.67 average
Chainer's Edict
8 copies - 2.67 average
Flame Slash
7 copies - 2.33 average
Terminate
7 copies - 2.33 average
Stinkweed Imp
6 copies - 2 average
Gorilla Shaman
5 copies - 1.67 average
Palace Sentinels
5 copies - 1.67 average
Prismatic Strands
5 copies - 1.67 average
Wind-Scarred Crag
4 copies - 1.33 average
Scoured Barrens
4 copies - 1.33 average
Shrieking Grotesque
4 copies - 1.33 average
Mogg War Marshal
4 copies - 1.33 average
Tethmos High Priest
4 copies - 1.33 average
Electrickery
4 copies - 1.33 average