Merfolk
A Modern deck, by Justin Kujawski
5th place at a tournament in Bernardsville, New Jersey, United States on 2019-12-01
As reported at http://www.starcitygames.com

Maindeck:
4 Island

Artifacts
4 Aether Vial

Creatures
2 Brazen Borrower
4 Kumena's Speaker
4 Lord of Atlantis (Not currently legal in Modern)
4 Master of the Pearl Trident
4 Merfolk Mistbinder
4 Merfolk Trickster
4 Silvergill Adept

Enchantments
4 Spreading Seas

Instants
4 Force of Negation

Legendary Planeswalkers
2 Oko, Thief of Crowns (Banned in Modern)

Lands
4 Botanical Sanctum
2 Breeding Pool
1 Cavern of Souls
1 Misty Rainforest
3 Mutavault
1 Scalding Tarn
4 Waterlogged Grove

Sideboard:
3 Chalice of the Void
3 Relic of Progenitus
3 Collector Ouphe
2 Deprive
4 Dismember