Basically, they make it so that both spells and abilities that your opponents control cost an extra two mana to cast or activate if they target a Merfolk you control
There is a genuine delight in those times you're able to solve that Stax puzzle and come out on top

Kaza Wizard Tribal Kaza, Roil Chaser | Illustration by Ekaterina Burmak Commander (1) Planeswalkers (2) Kasmina, Enigmatic Mentor Ral, Storm Conduit Creatures (25) Aphetto Alchemist Apprentice Wizard Archmage Emeritus Azami, Lady of Scrolls Cyclone Summoner Docent of Perfection Dualcaster Mage Fatestitcher Goblin Electromancer Guttersnipe Harmonic Prodigy Information Dealer Laboratory Maniac Malevolent Hermit Manaform Hellkite Niv-Mizzet, Parun Nivix Guildmage Overwhelmed Apprentice Riptide Director Siren Stormtamer Stonybrook Banneret Storm-Kiln Artist Triskaidekaphile Veyran, Voice of Duality Vodalian Arcanist Instants (15) Abrade Brainstorm Comet Storm Cyclonic Rift Deflecting Swat Dramatic Reversal Goblin Wizardry Increasing Vengeance Invert // Invent Narset's Reversal Pongify Rapid Hybridization Reality Shift Refuse // Cooperate Swan Song Sorceries (16) Brass's Bounty Crackle with Power Doublecast Epic Experiment Expressive Iteration Expropriate Finale of Promise Finale of Revelation Invoke the Firemind Jaya's Immolating Inferno Mana Geyser Sea Gate Restoration Solve the Equation Soulfire Eruption Step Through Tasha's Hideous Laughter Enchantments (2) Artifacts (6) Arcane Signet Geistflame Reservoir Herald's Horn Isochron Scepter Pyromancer's Goggles Sol Ring Lands (33) Base Camp Desolate Lighthouse Island x13 Maze of Ith Minamo, School at Water's Edge Mountain x13 Mystic Sanctuary Reliquary Tower Shivan Reef I really like this hybrid style between wizard tribal and spellslinger decks

Oh, and if you want to read my Top Ten list for New Phyrexia, the link is below.
Card Set(s) Included in Event Pack Vol type or attribute Character card with a cost of 4 or less other than [Dracule Mihawk] from your hand rested
And if you're stuck, there's more in the bag to get your team up and running, like the boons and traits system providing additional buffs and bonuses in combat