Possibility Storm is a Aggressive Midrange strategy that has a backup combo to just win the game out of no where. With pioneer become a much faster format it is important for the best decks to attack from multiple ways, while one of the ways is just to close the game out quick.
Lets discuss the combo in the deck. First objective is to ramp and dig for Possibility Storm. Once it is on the battlefield, you need to cast either Dread Whispers or Heart's Desire to storm into Enter the Infinite. This forces you to draw your entire deck and you place Borborygmos Enraged as the only card in your library. You proceed to cast any creature to swap it for Borborygmos Enraged. Once Enraged is on the battlefield you discard all your lands to bolt your opponent for the win.
DECK LIST
MAIN DECK
Creature Breakdown
Ramp: Playing three copies of Llanowar Elves and four copies of Elvish Mystic for turn one ramp. So we can play a three drop turn two.
Combo Pieces: Running 4 copies of Mosswood Dreadknight and four copies of Lovestruck Beast because they trigger Possibility Storm to find our Enter the Infinite. Borborygmos Enraged is the threat we put on top of our library and we cast our one of Stonecoil Serpent with X = 0 to storm into Borborygmos.
Bonecrusher Giant: Is a solid threat that can answer small threats from our opponent.
Hazoret the Fervent: Is a solid threat against midrange and control that is hard to answer.
Noncreature Breakdown
Core Spells: Three copies of Possibility Storm, due to it being five mana and is often clunky in multiples. We run other ways to turn through our deck to find a copy. Running one copy of Enter the Infinite, due to it being our combo finish piece with Storm.
Setup Pieces: The deck runs four copies of The Huntsman's Redemption to tutor for our cards that give us an adventure that is a Sorcery. Plus is a solid three drop that applies pressure. Fable of the Mirror-Breaker is another solid three drop that makes a goblin that creates treasures to help ramp us, while also providing card filtering to find our Possibility Storm.
Removal Suite: Running three Volcanic Spite that can deal with smaller creatures while also putting our Enter the Infinite or Borborygmos Enraged to the bottom of the library for the combo.
Valakut Awakening: Providing the 23rd land, that also functions as away to put Enter the Infinite or Borborygmos Enraged to the bottom of the library for the combo.
Sideboard Breakdown
Removal Suite: Two rending volley for matchups where we need to answer Ledger Shredder, Angels, Greasefang, Convoke Threats, and etc. Two copies of Pick Your Poison to answer Atraxa and artifacts or enchantments.
The Huntsman's Redemption Suite: Running 2 copies of Rampaging Ferocidon to stop Angels, by preventing life gain. Running two copies of Tranquil Frillback for a creature that is graveyard, artifact, and enchantment hate. Also provides life gain vs aggressive decks. Krenko's Buzzcrusher is a piece we can bring in to destroy a lotus field. Klothys, God of Destiny is a target that helps against graveyard decks and against control.
Skylasher: It helps against Spirits and it is key against Sheoldred to combo through her. Otherwise drawing your entire library will cause you lose.
Reckoner Bankbuster: Running two copies to provide card advantage against the grindy matchups.
Damping Sphere: Running two copies to help bridge the gap against Lotus Field that wins by turn five.
Sideboard Guide
Rakdos Prowess
Azorius Control
Izzet Phoenix
Jund Sacrifice
Enigmatic Incarnation
Next we will cover non tier one decks that you might face.