Merfolk
A Modern deck, by Jessie Hedman
2nd place at a tournament in Syracuse, New York, United States on 2017-11-04
As reported at www.starcitygames.com

Maindeck:

Artifacts
4 Aether Vial

Creatures
4 Cursecatcher
3 Harbinger of the Tides
4 Kumena's Speaker
4 Lord of Atlantis (Not currently legal in Modern)
4 Master of the Pearl Trident
4 Merfolk Branchwalker
3 Merrow Reejerey
4 Silvergill Adept

Enchantments
4 Spreading Seas

Instants
2 Dismember

Legendary Creatures
1 Kopala, Warden of Waves

Basic Lands
4 Island

Lands
4 Botanical Sanctum
2 Breeding Pool
4 Cavern of Souls
4 Mutavault
1 Unclaimed Territory

Sideboard:
3 Relic of Progenitus
2 Chameleon Colossus
3 Ceremonious Rejection
2 Dispel
4 Natural State
1 Unified Will