Most played cards in Merfolk:

1 Decks
Cursecatcher
4 copies - 4 average
Cavern of Souls
4 copies - 4 average
Force of Will
4 copies - 4 average
Mutavault
4 copies - 4 average
Chalice of the Void
4 copies - 4 average
Master of the Pearl Trident
4 copies - 4 average
Lord of Atlantis
4 copies - 4 average
Silvergill Adept
4 copies - 4 average
Phantasmal Image
4 copies - 4 average
True-Name Nemesis
4 copies - 4 average
Back to Basics
3 copies - 3 average
Mistcaller
3 copies - 3 average
Aether Vial
3 copies - 3 average
Surgical Extraction
2 copies - 2 average
Daze
2 copies - 2 average
Merfolk Trickster
2 copies - 2 average
Grafdigger's Cage
2 copies - 2 average
Spell Pierce
1 copies - 1 average
Echoing Truth
1 copies - 1 average
Chill
1 copies - 1 average