Mainboard
Creatures
Thraben Inspector: A great 1-drop, and our only 1-drop. Gets us some card advantage and acts mostly as a blocker for early creature pressure, although it can also get blinked by Thassa and Yorion to provide more opportunities to fill our hand.
Charming Prince: A must-have playset. The value we generate from the Prince is expanded heavily with our engine, since we can get anything we need out of it. Need to set up your next couple of turns? Scry. Dealing with some aggression? Gain 3 life. It even blinks a creature himself in case we're still looking for Thassa.
Guardian of Ghirapur: A solid card. Fits the blink theme and acts as a beater in the air as well. Maybe a bit redundant though.
Elite Spellbinder: Okay, so, what if we played Invasion of Gobakhan
, but we did it every turn? Wouldn't that be cool?
Arcanist's Owl: Another simple piece, but one that can get us an answer to a problem much earlier than we would normally. Blinking this every turn with Thassa means we more than likely have an answer every turn. Also a solid beatstick, and makes Thassa a creature just by existing.
Archon of Sun's Grace: One of our several wincons. Kind of a no-brainer since we run so many enchantments, especially since we can blink them with Yorion and recur them with Heliod, the Radiant Dawn
. The extra lifegain is nice.
Thassa, Deep-Dwelling: The engine. She only hits creatures, but it's still a very effective strategy. Feel free to blink Archon after an attack to keep a blocker up as well.
Heliod, the Radiant Dawn
: An enchantment recursion piece, plus he's an enchantment himself. Gets sagas back into our hand from the yard, and if we really need to (although in testing on Arena, I have never done this), we can transform him to get a bigger body or to change our responses to threats with our enchantments, since none of them have flash to begin with. He's a really funny Thassa target.
Enchantments
The Birth of Meletis: A great early drop. Guarantees some mana, gets us a beefy blocker, and gets some life. A cheap recur target for Heliod, and isn't always a dead draw late game, especially with Archon out.
Omen of the Sea: Unironically one of my favorite enchantments in the whole deck. Turn two, instant speed, scry 2 and draw. We can blink this with Yorion and recur it if we decide to sacrifice it for more scrying. Really cheap card, and in my opinion, much better than Thirst for Meaning.
Touch the Spirit Realm: Solid removal, but it also has an added benefit of blinking our creatures at instant speed, meaning we can protect against removal. Plus, we can channel it, and then bring it back with Heliod, which is REALLY funny.
Detention Sphere: Very good card for one reason; it hits more than just creatures. In game one, this hits Karn, the Great Creator, Witch's Oven, Fable of the Mirror-Breaker
, and any vehicle your heart desires, plus creatures. Also hits multiple targets if they have them, good against decks like Humans.
Elspeth Conquers Death: This is my favorite enchantment in the deck. Exiles big and important things, keeps control and combo decks in check a little better, and brings back creatures. This is the funniest thing to bring back with Heliod.
Kiora Bests the Sea God: This is also really funny, but because of the cost, we only run one copy. If we hit it and cast it though, it's pretty much game over for the opponent. Also something we can blink with Yorion, which just makes this funny.
Battles
Invasion of Gobakhan
: This is just a good card. It'll be easy to take out with our fliers (since three of them have enough power to take it out in one hit) and can spur us to a much quicker victory. We can also blink this with Yorion to get the exile trigger again.
Invasion of Theros
: Finds us Thassa, and if we blow this up, Ephara, Ever-Sheltering
is nutty. Plus we can blink this with Yorion to grab Heliod too.
Instants/Sorceries
Syncopate: A tempo killer and a counterspell that doesn't get bad the further into the game we go.
Absorb: A great counterspell in our colors.
Sideboard
Yorion, Sky Nomad: Hey, look, it's the funny guy!
Mystical Dispute: Another counterspell option in the side against the control mirror.
Rest in Peace: (Insert obligatory Rak Sac/Greasefang comment here). Note that this card completely negates our own ability to recur our cards, so when siding this in, just take out the Heliods.
Runed Halo: A good card against an aggro or midrange in general, but also completely shuts down Bogles, which has been getting oddly popular lately (at least for me).
Seal Away: A true aggro killer. Cheap removal at instant speed for us.
Temporary Lockdown: I REALLY hate aggro, in case you couldn't tell. On a serious note though, this almost completely shuts down humans, and even has some use against Rak Sac, albeit not as much.