Merfolk
A Modern deck, by Alan Cummings
5th place at a tournament in Knoxville, Tennessee, United States on 2018-05-12
As reported at www.starcitygames.com

Maindeck:

Artifacts
4 Aether Vial

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

Enchantments
4 Spreading Seas

Instants
2 Dismember
2 Spell Pierce

Legendary Creatures
2 Kira, Great Glass-Spinner

Basic Lands
12 Island

Lands
2 Cavern of Souls
4 Mutavault
1 Wanderwine Hub

Legendary Lands
1 Oboro, Palace in the Clouds

Sideboard:
3 Relic of Progenitus
2 Tidebinder Mage
2 Ceremonious Rejection
4 Deprive
2 Dispel
2 Echoing Truth