Mid-power Big Mana Sea Monsters!

Gameplan:

Early game ramp into big sea monsters, then making them unblockable to swing for game.
Arixmethe's commander damage makes him a two-turn kill when paired with cards like Artful Dodge, Archetype of Imagination or Deepchannel Mentor.

There's a large focus on dual function creatures, like the landcyclers that can be lands in the early game or big creatures if drawn later. Mirrorshell Crab and Sword Coast Serpent are also examples of late-game bombs that are useful early. This way the deck can still have a large density of threats while staying interactive and consistent.

Deck Lore:

This deck aims to tell the story of the isle of Arixmethes.

It starts off with lots of smaller green creatures, like Elvish Mystic or Voyaging Satyr, who live on Arix, unaware of what the island really is.
As the game goes on and we get more mana, the island begins to wake up, slumber counters are removed, more and more sea monsters are cast.
Finally, the island fully awake, cards like Slinn Voda, the Rising Deep and Whelming Wave wash all other creatures away, leaving just the sea monsters to win the game!