Merfolk
A Modern deck, by Louis Anderson
105th place at a tournament in Valencia, Spain on 2014-02-23

Maindeck:
15 Island

Artifacts
4 Aether Vial

Artifact Creatures
1 Spellskite

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

Enchantments
4 Spreading Seas

Instants
1 Disrupting Shoal
1 Spell Pierce
3 Vapor Snag

Legendary Creatures
1 Vendilion Clique

Legendary Enchantment Creatures
1 Thassa, God of the Sea

Lands
2 Cavern of Souls
4 Mutavault

Sideboard:
2 Grafdigger's Cage
1 Relic of Progenitus
2 Spellskite
1 Tidebinder Mage
3 Sensory Deprivation
1 Gut Shot
2 Hurkyl's Recall
1 Negate
1 Steel Sabotage
1 Swan Song