I'm very new to magic, but I have created my second deck based on Sea Monsters.
The purpose of the deck is pretty simple.
Most of the damage dealing creatures are high cost Krakens, Leviathans, and other big baddies.
In the early game try and rush Wall of Frost, then tap Alluring Siren to force the player to attack Wall of Frost. This will cause any creature to not untap during its next untap step. Biding you time.
The Instance deck:Unsummon exists as well to help shove back enemy creatures while you gain enough land for your high cost creatures.
Rite of Replication will give a clone of one your big monsters as well as the Kicker 5 cost if you get to it.
Tome Scour and Traumatize will be great at catching them off guard. (As long as they don't have counters). This isn't a mill deck but these powerful cards will make the player run out of options giving you time to get out the Sea Monsters.
deck:Walking Dream is amazing at attacking with unblockable while you have walls up. Allowing you to drain the enemy down if you're unable to play the Sea Creatures.
Very open to suggestions, the deck cost me about $30.00 and pretty good for affordability.
-Dylan H. Lloyd