Merfolk
A Modern deck, by zaque arnold
1st place at a tournament in Littleton, Colorado, United States on 2014-08-16
As reported at www.starcitygames.com

Maindeck:

Artifacts
4 Aether Vial

Creatures
1 Coralhelm Commander
3 Cursecatcher
4 Lord of Atlantis (Not currently legal in Modern)
4 Master of the Pearl Trident
2 Master of Waves
4 Merrow Reejerey
3 Phantasmal Image
4 Silvergill Adept

Enchantments
4 Spreading Seas

Instants
3 Vapor Snag

Legendary Creatures
2 Kira, Great Glass-Spinner

Legendary Enchantment Creatures
1 Thassa, God of the Sea

Basic Lands
12 Island

Lands
4 Cavern of Souls
4 Mutavault
1 Tectonic Edge

Sideboard:
1 Grafdigger's Cage
2 Torpor Orb
2 Spellskite
2 Tidebinder Mage
1 Threads of Disloyalty
1 Dismember
2 Echoing Truth
2 Hurkyl's Recall
2 Steel Sabotage