Most played cards in Cephalid Breakfst:

2 Decks
Force of Will
8 copies - 4 average
Polluted Delta
8 copies - 4 average
Swords to Plowshares
8 copies - 4 average
Ponder
8 copies - 4 average
Flooded Strand
8 copies - 4 average
Cephalid Illusionist
8 copies - 4 average
Brainstorm
8 copies - 4 average
Prismatic Ending
7 copies - 3.5 average
Nomads en-Kor
6 copies - 3 average
Stoneforge Mystic
6 copies - 3 average
Urza's Saga
6 copies - 3 average
Narcomoeba
6 copies - 3 average
Daze
5 copies - 2.5 average
Teferi, Time Raveler
5 copies - 2.5 average
Tundra
5 copies - 2.5 average
Step Through
4 copies - 2 average
Shuko
4 copies - 2 average
Serenity
4 copies - 2 average
Surgical Extraction
4 copies - 2 average
Flusterstorm
4 copies - 2 average