Merfolk
A Legacy deck, by Gregory Hatch
2nd place at a tournament in Las Vegas on 2013-12-14

Maindeck:

Artifacts
3 Aether Vial

Creatures
3 Cosi's Trickster
4 Cursecatcher
4 Lord of Atlantis
4 Master of the Pearl Trident
3 Merrow Reejerey
3 Phantasmal Image
4 Silvergill Adept
4 True-Name Nemesis

Instants
4 Daze
4 Force of Will

Basic Lands
12 Island

Lands
4 Cavern of Souls
4 Mutavault

Sideboard:
1 Grafdigger's Cage
1 Pithing Needle
2 Relic of Progenitus
1 Spell Pierce
3 Submerge
4 Swan Song
1 Vision Charm
1 Umezawa's Jitte
1 Llawan, Cephalid Empress