Under the Sea~ If you're not one of 'em fish kins, you're in deep trouble.
I'm sorry if I disappoint the general public due to the lack of Dimir cards or other more feasible spells. But that' just the way I work, flavor over power.
The deck started off pretty silly with no apparent goal, after struggling with myself on whether should I splash black, I finally came to a decision, Fine! I shall introduce Wrexial and Nemesis to the deck. With that, so came the big fishes.
KEY CARD!
Quest for Ula's Temple - Just like any mmorpg or rpg, a Quest is rewarding (well, some of them are). This one drop enchantment will accumulate Quest counters during your upkeeps IF you reveal the top of your library and it happened to be a creature (Thus the creature count for this deck is pretty high). Once you have 3 counters on this Enchantment, check your hand for a Leviathan, Kraken, Octopus or Serpent. Because at the end of the turn, one of 'em bad boys will crash into the field.
INSTANTS
Thought Scour - Pretty little card with a pretty art, mill two, draw one. One drop.
Think Twice - the flexible and cheap instant for card advantage!
CREATURES
I'll save the big fishes for later, let's look at the smaller, seemingly harmless ones first.
Hedron Crab - If you're gonna mill, this little guy will bring the pain for the early game, as early as Turn 1. Cast it, and it shall watch for landfall, one land entering the field under your control = mill 3.
Jace's Phantasm - The only reason why I added this card is because it resembles a manta-ray. 1 drop with flying and gets +4/+4 when your opponent's graveyard have 10 cards? Definitely a mid-game threat. (Unless of course your opponent happen to play Wheel of Sun and Moon)
Void Stalker - for 2 mana to cast, for 3 mana you can return it to the top of your library, same goes for a creature that an opponent controls. This is a great technique to stall the game and to assure Quest for Ula's Temple to reveal a creature. Guess who I'm about to draw? Void Stalker~!
Guard Gomazoa - Nobody gets pass the bouncer, nobody, no first strike, double strike, trample, infect or bushido. 3 mana flying defender with an attitude, it takes no damage from nobody!
Sage Owl - Not a sea creature at all, but to Scry is important to a deck with Quest for Ula's Temple, I chose this card because I can't afford to get the more costly scry spells such as Serum Vision.
Deep-Sea Kraken - Suspend for 3 mana and watch it crawl out towards your fear-stricken opponent for each spell they cast? Or simply wait for the Quest to send it down at the end of your turn? 6/6 Unblockable, quite the deal here.
Isleback Spawn - Shroud with 4/8, and it gets buffer if a library hits below its 20-card mark, this ground-slapping tide-shaping monster will become 8/16. Besides having a deathtouch creature under their control, I can't think of any other reason why the opponents should NOT be afraid.
Lorthos the Tidemaker - Torrents after torrents of waves, tap 8 when the Mollusk attacks, and you tap 8 permanents! They don't untap during their next untap step... Revenge of the Takos
Nemesis of Reason - What is this I don't even- Yes, that's the Nemesis of reason, when it attacks, whether blocked or not, damage dealt or not, your opponent mills 10, no questions.
Stormtide Leviathan - What the... Yeah, this big fish is ridiculous, 8/8 with islandwalk. All lands becomes island in addition to their own types. Creatures with flying or islandwalk cannot attack... It basically cripples your own creatures too, so choose wisely. (Or just get Levitation)
Wrexial? Well he pretty much will come out of the card and strangle your opponent. Nah I'm kidding, he has islandwalk and swampwalk, and when he lays a hit on your opponent, you may cast an instant or sorcery from their graveyard without paying the Mana Cost. Pretty sweet huh?
DAT LAND
As per usual, I don't play shock lands or such, they burn my wallet.
So I stick to simpler non-basic lands, Nephalia drownyard, got extra mana to spare? Always good to mill 3 before your turn comes around since there won't be much to spend on when it's not your turn.