Most played cards in Underworld Dreams Combo:

2 Decks
Dark Ritual
8 copies - 4 average
Underworld Dreams
8 copies - 4 average
Howling Mine
8 copies - 4 average
Winds of Change
8 copies - 4 average
Lightning Bolt
8 copies - 4 average
City of Brass
8 copies - 4 average
Underground Sea
8 copies - 4 average
Badlands
8 copies - 4 average
Red Elemental Blast
6 copies - 3 average
Energy Flux
6 copies - 3 average
City in a Bottle
5 copies - 2.5 average
Boomerang
5 copies - 2.5 average
Flash Counter
5 copies - 2.5 average
Ivory Tower
5 copies - 2.5 average
Volcanic Island
4 copies - 2 average
The Abyss
3 copies - 1.5 average
Blue Elemental Blast
3 copies - 1.5 average
Library of Alexandria
2 copies - 1 average
Sol Ring
2 copies - 1 average
Mox Ruby
2 copies - 1 average