Much of the excitement behind Pioneer has been fueled by the repurposing of old Standard decks that aren't broken enough to play in Modern. In the first few months, players were digging out old deck boxes that contained Temur Energy, Abzan Midrange, Eldrazi, Vampires, Delirium, and anything else they remembered from their wildly-misspent youth and slamming them on the table to play once again. Yes, the format has been overrun with interactions of newer cards like Thassa's Oracle and Lotus Field , but many of the more popular decks still spring out of the memories of yore.

For me, that meant Panharmonicon . Watching Seth's (PBKASA's) videos on a five-color Panharmonicon deck was one of the driving factors that actually got me to start playing Magic. I was so fascinated on how this one effect could let you draw all the cards, kill all the things, and win games that you had no business winning. So I started trying to come up with decks that would abuse ETB triggers. However, the problem with Panharmonicon decks are the same no matter what format you're in: the artifact usually does nothing on the turn that it enters the battlefield. If you play on curve, your turn 4 consists of playing the artifact and passing. And turn 4 is too important of a point in the game to do nothing.

But Theros Beyond Death provided a replacement with all the fun of Panharmonicon and much less downside in Thassa, Deep-Dwelling . Blinking creatures is almost as fun as doubling ETB triggers with some added benefits: it gets more value out of creatures you've already played, it untaps attackers and allows them to block again and it lets you control the effects that you want to repeat. All of this attached to an indestructible enchantment that every once in a while becomes a huge beater AND can tap down attacking creatures if your hand is empty?

She does everything.

So I took Thassa and replaced Panharmonicon with her in my UW Pioneer list, and she worked really well.

4 Thraben Inspector 4 Charming Prince 4 Fblthp, the Lost 3 Spell Queller 2 Deputy of Detention 4 Reflector Mage 3 Elite Guardmage 3 Ephara, God of the Polis 3 Thassa, Deep-Dwelling 4 Cloudblazer 1 Archangel Avacyn 1 Agent of Treachery 5 Island 8 Plains 4 Hallowed Fountain 4 Prairie Stream 4 Glacial Fortress 2 Rest in Peace 1 Hushwing Gryff 2 Declaration in Stone 2 Linvala, the Preserver 1 Settle the Wreckage 3 Dovin's Veto 3 Gideon's Intervention 1 Supreme Verdict

Sadly we don't have a Ephara, God of the Polis in the new Theros, because the Pioneer list has the added benefit of being a sort of Azorius Devotion because of the huge number of creatures it can play. But when I noticed that a little more than half of this list exists in current Standard, I thought that there would be a downshifted list that could compete.

It was not a smooth transition at first. I was under the impression that I could just replace creatures like Reflector Mage and Cloudblazer with analogues and everything would just work out. But the replacement creatures either weren't strong enough to be impactful ( Cloudkin Seer ), or were too easy to remove over time. Strangely, Deputy of Detention just isn't that good in Standard right now: there's too much easy bounce/creature removal that allows your opponent to get the extra ETB trigger. So the deck needed to go a different direction, and when I saw Nathan Zamora working on the same thing, his idea seemed to work: take advantage of Thassa's indestructibility and play a bunch of board wipes instead! So I started messing with his ideas, and I've had a lot of success on the ladders with it.

4 Charming Prince 4 Fblthp, the Lost 1 Alirios, Enraptured 4 Teferi, Time Raveler 4 Elite Guardmage 4 Thassa, Deep-Dwelling 2 Time Wipe 2 Cavalier of Dawn 1 Mesmirizing Benthid 3 Elspeth Conquers Death 1 Dream Trawler 2 Planar Cleansing 6 Plains 6 Island 2 Agent of Treachery 3 Castle Ardenvale 4 Hallowed Fountain 3 Temple of Enlightenment 2 Castle Vantress 2 Fabled Passage 2 Devout Decree 2 Disenchant 3 Dovin's Veto 4 Mystical Dispute 4 Absorb

The basic idea of the deck is not all that different. We want to play just enough card sifting and advantage in Charming Prince and Fblthp, the Lost early to reliably hit land drops and stay alive, slam a Thassa, and drown our opponent in card advantage and ETB triggers. The real difference is what we want to play when we get to that point. We add a copy of Alirios, Enraptured to have another creature producing attackers, and I've been experimenting with Mesmerizing Benthid to make even more blockers in aggro matchups and board stalls. We're using the usual UW Standard finishers in Elspeth Conquers Death and Agent of Treachery (for double the stealing), and Dream Trawler is just so good that I can't resist keeping a copy for the matchups where the opponent doesn't have an answer for it and it just wins. Cavalier of Dawn is surprisingly good as well... there are times when you don't really want to give your opponent a free 3/3 if you otherwise have an empty board, but Thassa provides an indestructible target for the ETB trigger that lets you get a 3/3 if nothing else is going on to block your opponent's gift.

However, the rest of the maindeck and the vast majority of the sideboard plays as a straight control deck. If you're UW in Standard, you have to run a playset of Teferi, Time Raveler . Them's the rules. But the real game-changers are Time Wipe and (especially) Planar Cleansing . Since one of your main threats is indestructible, wiping the board isn't as bad as you think it would be for a creature-based deck. Yes, you're starting the board over for both sides, but you're the one that gets to keep the god that taps down the opponent's team. And Planar Cleansing ... well, no one is playing around Planar Cleansing right now. Annoyed by Lucky Clover ? Opponent has a board full of planeswalkers? Wilderness Reclamation got you down? Planar Cleansing answers all of those things, AND leaves your Thassa behind!

The sideboard is almost completely for the UW Control list that's probably the best in Standard right now. We need Mystical Dispute and Dovin's Veto to win counterspell battles, and Absorb when we're REALLY desperate. Yes, you could almost do a sort of transformational sideboard where our list BECOMES UW Control, but I can't speak to this well because I'm not a great control player so I avoid this option like the plague. I like my creatures. Otherwise, there's Disenchant to have some spot enchantment and artifact removal, and Devout Decree for Lili, Chandra, and aggro.

It's certainly a competitive list, and it's also a deck that can be modified and changed over time as new sets come out. It's going to be hit by rotation, but Thassa will find a home somewhere as time passes and a lot of her toys are going to hang out or even improve with new sets. Give it a try and let me know what you think, and as always... drive friendly!