Last Sunday I played a 14man tournament with merfolk and ended up 3rd behind a countertopdeck with painter/stone and a RGb AggroLoam deck.
I went 4-2-0
This is my list:
//Lands:
13 Island
4 Wasteland
3 Mutavault
//Creatures:
4 Cursecatcher
4 Silvergil Adept
4 Lord of Atlantis
4 Merrow Rejeerey
4 Merfolk Sovereign
//Stuff:
4 Aether Vial
4 Daze
4 Standstill
4 Force of Will
2 Echoing Truth
2 Umezawa's Jitte
//Sideboard:
4 Hydroblast
1 Echoing Truth
1 Umezawa's Jitte
3 Stifle
2 Threads of Disloyalty
4 Spell Snare
To be honest, I created the sidebaord/pile in a rush so it's really subpar.
I lost the first match to AggroLoam, won the second and third to UBW countertop/faeries and UGR countertop with Coatl, Lost the fourth to Canadian Thresh and won the fifth and sixth to Merfolk and the winner of the tournament playing UGwb countertop with painter/stone.

