I have a very odd goal as a player: to build goofy and thematic/flavorful decks capable of getting to god rank, rather than building the best deck I can. This deck was inspired by Demonic Salmon; an edgier version of what was already my favorite card in the game. Wanting to play as many salmons as I could, I created the fishiest deck I could manage, and was able to reach god rank with it today.
It uses difficult to remove creatures like Drakkar Skycaptain, Manta Rider, and Skyward Swordfish to maintain board control, while Skycaptain makes ultraefficient removal out of the salmons, or turns Demonic Salmon into a very cheap 3/3-at-their-face threat. Salmons also make for excellent HP adjusters for setting Spirit Theft up. Swarming Carassius is of course quite good even without a shell that supports it mechanically (though I sure support it thematically), and a salmon can also be used to summon a carassius in otherwise inaccessible places.
In the end I was able to play 14/30 fish based cards and reach god rank (I... think mantas are fish right?). Please enjoy GY Fishies.