I am usually a UB Tendrils player, but I've been playing the deck so much lately that I opted to play something else to take a week off from preparing for an upcoming event. I brew'd a Merfolk list based on a Modern deck that I've been building some some friends. The list was as follows:
Lands
3 Island
1 Swamp
4 Underground Sea
4 Polluted Delta
1 Misty Rainforest
4 Mutavault
3 Wasteland
Creatures
4 Cursecatcher
4 Silvergil Adept
4 Lord of Atlantis
4 Coralhelm Commander
4 Merrow Reejerey
1 Kira, Great Glass Spinner
4 Dark Confidant
Spells
4 Force of Will
3 Spell Pierce
2 Daze
2 Dismember
Sideboard
4 Leyline of the Void
3 Engineered Plague
1 Nature's Ruin
1 Dismember
2 Null Rod
1 Kira, Great Glass Spinner
3 Flusterstorm
I went 2-2 in the swiss and somehow advanced on tie breakers and ended up winning out making it to finals and drew to split the prize money.
In the swiss, I lost to Reanimator and Ur Counterbalance with Dreadnoughts. I beat Goblins and Ub Tezzeret artifacts.
Dark Confidant was easily the MVP of the day for me. I rarely lost a game in which I resolved a Dark Confidant. It allowed me to keep pace with Goblins when they would usually overrun Merfolk with the card advantage generated by Siege-Gang Commander and/or Goblin Ringleader. It also allowed me to draw into enough countermagic to edge out Reanimator in the first elimination round. I'm not familiar with the finer points of piloting Merfolk, but Dark Confidant seems like a great addition as it adds an element of card advantage. Additionally other decks now have to use their removal spells on Confidant instead of killing your lords. While I did not get the opportunity to test this, my guess would be that Dark Confidant would give you an edge in the mirror match as well.
I found the Reanimator match-up to be somewhat difficult. I lost 0-2 in the swiss and won a very intense match 2-1 in the first elimination round. Elesh Norn, Grand Cenobite is nearly impossible to overcome. Two out of the three games I lost where due to a resolved Norn. The hands I kept that ended up being successful where ones in which I had a turn one disruption play backed up by a free counterspell. For example, turn one Cursecatcher backed by either Daze or Force of Will. If you're not casting Cursecatcher turn one, I usually held up mana for Spell Pierce or Flusterstorm (backed by Daze or Force of Will). My short experience in this match has led me to believe that you forgo casting a turn two spell and wait until turn three to cast a threat. The reason why is Reanimator almost always plays Daze. So leaving mana up to pay for it effectively blanks one of their counterspells. While I boarded in Leyline of the Void, I never found it in my opening hand so its hard for me to make an assessment of its value. Moving forward, I would still keep Leyline in the sideboard. However, I think most Reanimator lists will adopt a Show and Tell in the maindeck and at least two more in the board so it is not a total solution. Flusterstorm was particularly useful in this match-up as it dominated the stack. The one thing to be wary of is that some lists are now running Animate Dead in an increasing quantity. This can make hands that have Cursecatcher and Flusterstorm somewhat risker. I would suggest using Cursecatcher and Flusterstorm to counter the Entomb or Careful Study if you put them on more than one Animate Dead.
Moving forward, I would make the following changes:
Maindeck
-Minus one Swamp, plus one Watery Grave: I wanted to try a basic Swamp because have access to a basic seemed nice given the amount of black cards in the maindeck and in the board. Upon further reflection, I think switching to Watergrave seems correct. It does the best Undergroudn Sea impression out there. I lost one game because I drew the Swamp early and couldn't generate the necessary blue mana to stay in the game. The list doesn't need access to black mana since Dismember can be cast for free and you can Vial in Dark Confidant if need be. The sideboard cards are have a single black mana in the casting cost (Leyline excluded), and the deck will be running ten ways to access black mana which seems sufficient.
Sideboard
-I would take out the single copy of Nature's Ruin. Plague covers the Elves match up while Dismember solves Tarmogofy issues. Nature's Ruin could stay in if I needed a solution to NO.dec. However, I think a copy or two of Phantasmal Image solves this issue just as well and has added value in other match-ups as well.
-Null Rod seems like the odd card because it shuts off Aether Vial. However, we had at least three decks of the B/W or mono white variety that played copious amounts of equipment. Null Rod seems like a great solution these decks as their creatures look much less impressive if you shut off their equipment.
