This is my unblockable merfolk deck that has a minor energy theme primarily for post-board.
Main Deck
Creatures
Kumena's Speaker is a 1/1 for which becomes a 2/2 if you have an Island on board or another merfolk. It's a great one-drop because almost every time it'll be a 2/2 attacking on turn 2.
Metallic Mimic is a great two-drop because naming merfolk as its creature type ensures that all following merfolk ETB with a +1/+1 counter which is exactly what this deck wants!
Deeproot Warrior may be a 2/2 for , but if it gets blocked when attacking it's essentially a 3/3. If your opponyour chooses to block with their 2/2, then you eat their creature and if they only have a 3/3 on board and they block, it trades up! It gets even better after the +1/+1 counter from Mimic.
Merfolk Branchwalker is another two-drop except this one has pseudo-scry 1 with the potential to ETB as a 3/2 rather than a 2/1. Again, as with the Deeproot Warrior, it likes coming in after Mimic.
River Sneak is a 1/1 for which seems pretty bad, but being unblockable and getting +1/+1 until EOT for each merfolk played that turn makes it a solid two-drop. Playing it before Mimic even isn't a bad play as the Mimic will pump it that turn!
Vineshaper Mystic is a solid three-drop and is perfect in this deck as it hits all my merfolk. Okay, not technically all of them since it can only dish out one +1/+1 counter to up to two merfolk, but it has many targets including itself. Solid A!
Herald of Secret Streams is what brings this deck to life. For four mana, it comes in and makes all creatures with +1/+1 counters on them unblockable! It's a solid merfolk and for what this deck wants, it's an easy A+.
Rogue Refiner is the one creature here that stands out the most. It doesn't get pumped from merfolk Mimic and Vineshaper's Mystic won't touch it, either. However, a 3/2 body for that also draws me a card just isn't bad. It also provides two energy counters which works with Aether Hub and is especially viral post-sideboard.
Spells
Blossoming Defense is a solid protection/pump spell that only costs . This deck has 30 creatures in it and I don't want a single one going down to Vraska's Contempt, Fatal Push, or Walk the Plank! Targeted removal spells? Get the hell out of here!... Also, just kidding about that last removal spell.
River Heralds' Boon
is am excellent combat trick in this deck and even allows you to pump the Rogue Refiner for a single +1/+1 counter.
Glimmer of Genius is here because sometimes you empty out your hand and just want to draw more. Scrying two and then drawing two ensures that you get what you want (or pass up on what you don't want). The two energy help Aether Hub and go well with post-sideboard games.
Sideboard
Aethersphere Harvester and Life Goes On are both here for aggro games. Life gain is what aggro hates and using energy to give the Harvester lifelink is super solid, especially on a 3/5 flying body that only has a Crew 1 cost. The latter spell is great for gaining life immediately and if they took out a creature, just play Life Goes On and gain eight life instead of four.
Confiscation Coup is another energy-caring card that costs a hefty five mana. Though, it provides you with four energy and with whatever other energy you have, you can use it to pay energy equal to an opponent's creature's mana cost and straight up steal it from them. The best part is that it isn't until EOT, it's for the whole game!
Dissenter's Deliverance is here for those God-Pharoah's Gift decks! They're a pain in the ass. It also works on other artifacts like the gearhulks. It also has a cycle cost of in case it's just doing nothing in your hand.
Jade Guardian has protection from spot-removal with hexproof and pumps a merfolk with a +1/+1 counter, including itself.
Negate and Supreme Will fill about the same roll. They make you slightly more controlling and help against boardwiping spells like Fumigate. Also, Supreme Will has a second option that allows you to dig for that one spell you really need in your library!
Island is here because there're a lot of blue spells in the sideboard and only six Island in the main deck.
