Not every deck can make it through the rigorous Pro Tour testing gauntlet. Sometimes the deck builders can't arrive at quite the right combination of cards, or the brew is too likely to lose to a popular deck in the field, or it's a casualty of sideboard cards intended to be good against other decks.
It was because of sideboard cards intended to beat the Saheeli Rai/Felidar Guardian combo that Marc Tobiasch, a member of Team EUreka, didn't play a mono-blue Paradoxical Outcome and Aetherflux Reservoir "storm" deck he'd been testing up until two days before the Pro Tour.
While Team EUreka member Marc Tobiasch ultimately shelved the deck for this Pro Tour, Aetherflux Reservoir has the makings of something special in the right format.
"Right now, it's a lot of Negates and Dispels running around because of the Saheeli combo," Tobiasch said. "It's very tough to have to fight through those because all your spells get countered by Negate or Dispel."
Zero-cost equipment, or colorless moxen, if you look at things the way Tobiasch does with what these cards are doing.
Once you've played a handful, you return them to your hand with Paradoxical Outcome, and draw three or four more cards. You then play the equipment again, generating "storm," or a high number of spells cast in a single turn, for Aetherflux Reservoir.
"Usually you need eight or nine spells," Tobiasch says of the deck's winning turns.
The deck may sound familiar to players who saw or tried a version of this deck in the early days of Kaladesh Standard. The deck wasn't competitive, but with Aether Revolt came some additions that give the deck more consistency and an added boost in power.
"There's Whir of Invention now, which you can tap your moxen for, to get the Aetherflux Reservoir," Tobiasch said. "Also, I was playing one Inspiring Statuary, so you can actually tap your moxen to play the Paradoxical Outcome, so it only costs one mana. You return the moxen, play them again, and play the next Outcome, and you chain through your deck."
The deck's unique composition creates a tricky target for other decks in the field to take aim at with their usual suite of creature removal spells.
"It's very hard for opponents to interact with this because the only creature in the deck is Torrential Gearhulk. You can get that with a Whir of Invention, which is pretty nice," Tobiasch said. "A lot of the time your early game is playing some moxen, drawing cards with Reverse Engineer, and then playing some more moxen and then casting Paradoxical Outcome for three or four cards."
Despite the advantage of creature removal having few targets versus the Paradoxical Outcome deck, the Negates and Dispels players have in their sideboards are too often enough. Paradoxical Outcome Storm is a little light on interaction itself, making one well-placed counterspell more brutal than usual.
"This makes it very difficult because your interaction with your opponent isn't killing their cards," Tobiasch said. "The only cards you have that interact with your opponent are Metallic Rebuke and Engulf the Shores, but Engulf the Shores gives them their cards back, and once they stop you from comboing for a while, they can replay their cards. That makes it hard."
"I think it might be very good if the metagame shifts a little bit away from Saheeli," Tobiasch said. "If people play more Black-Green or Mardu Vehicles, things like that, those are really good matchups."
So don't toss out those Cathar's Shields quite yet, as they might yet be destined for a player library near you in the coming months.