Merfolk
A Modern deck, by Peter DeBorja
1st place at a tournament in California, Maryland, United States on 2017-03-04
As reported at www.starcitygames.com

Maindeck:

Artifacts
4 Aether Vial

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

Enchantments
4 Spreading Seas

Instants
2 Dismember
2 Spell Pierce

Legendary Creatures
2 Kira, Great Glass-Spinner

Basic Lands
10 Island

Lands
2 Cavern of Souls
4 Mutavault
1 Wanderwine Hub

Legendary Lands
1 Minamo, School at Water's Edge
1 Oboro, Palace in the Clouds

Sideboard:
2 Chalice of the Void
1 Dragon's Claw
2 Relic of Progenitus
2 Dispel
2 Echoing Truth
2 Hurkyl's Recall
3 Unified Will
1 Vendilion Clique