Most played cards in Power Monolith:

5 Decks
Power Artifact
20 copies - 4 average
Basalt Monolith
20 copies - 4 average
City of Brass
19 copies - 3.8 average
Volcanic Island
17 copies - 3.4 average
Red Elemental Blast
16 copies - 3.2 average
Fireball
15 copies - 3 average
Power Sink
14 copies - 2.8 average
Transmute Artifact
13 copies - 2.6 average
Underground Sea
10 copies - 2 average
Shivan Dragon
8 copies - 1.6 average
Fellwar Stone
7 copies - 1.4 average
Guardian Beast
6 copies - 1.2 average
Icy Manipulator
6 copies - 1.2 average
Mox Sapphire
5 copies - 1 average
Mox Ruby
5 copies - 1 average
Wheel of Fortune
5 copies - 1 average
The Abyss
5 copies - 1 average
Mox Pearl
5 copies - 1 average
Timetwister
5 copies - 1 average
Time Walk
5 copies - 1 average