Most played cards in Ninja:

1 Decks
Force of Will
4 copies - 4 average
Changeling Outcast
4 copies - 4 average
Ingenious Infiltrator
4 copies - 4 average
Ornithopter
4 copies - 4 average
Brainstorm
4 copies - 4 average
Ponder
4 copies - 4 average
Polluted Delta
4 copies - 4 average
Prismatic Vista
4 copies - 4 average
Retrofitter Foundry
4 copies - 4 average
Daze
3 copies - 3 average
Fatal Push
3 copies - 3 average
Yuriko, the Tiger's Shadow
3 copies - 3 average
Narset, Parter of Veils
2 copies - 2 average
Back to Basics
2 copies - 2 average
Grafdigger's Cage
2 copies - 2 average
Plague Engineer
2 copies - 2 average
Thoughtseize
2 copies - 2 average
Flusterstorm
1 copies - 1 average
Massacre
1 copies - 1 average
Surgical Extraction
1 copies - 1 average