I have had a great time tinkering and re-tinkering with a Possibility Storm/Gifts Ungiven modern package. While probably just too weak to discard, this deck is a ton of fun. Here's my list for anyone trying to fool around with a Possibility Storm deck:
Long-time lurker, first time poster. This deck is really fun, but competitively feels like it needs something to make it more powerful and consistent. I've been tinkering around with Possibility Storm and was wondering if the multiple cast triggers that you get off of it can help prevent the deck from running out of gas. It also allows you to turn 1 mana Ancient Stirrings into Wildfire or Destructive Force. And it would also allow us to have the alternate wincon of Storming a Walking Ballista into an Emrakul, the Aeons Torn. Probably too cute, but I tend to have many turns where I either run out of gas or give my opponent too many answers when they draw off of my Otherworld Atlas and wanna look for other avenues to explore with this list.
1 Beacon of Destruction
3 Blood Moon
1 Cascade Bluffs
2 Cryptic Command
1 Desolate Lighthouse
1 Emrakul, the Aeons Torn
1 Enter the Infinite
3 Gifts Ungiven
1 Indomitable Creativity
3 Island
2 Izzet Charm
4 Lightning Bolt
1 Mountain
1 Mutavault
1 Noxious Revival
4 Opt
1 Pact of Negation
4 Polluted Delta
1 Polymorph
2 Possibility Storm
4 Remand
4 Scalding Tarn
1 Snapcaster Mage
1 Snow-Covered Island
3 Spreading Seas
2 Steam Vents
2 Sulfur Falls
2 Supreme Will
1 Temple of Epiphany
1 Tolaria West
1 Zoetic Cavern
1 Commandeer
1 Dispel
3 Gigadrowse
2 Hurkyl's Recall
1 Keranos, God of Storms
2 Kozilek's Return
2 Negate
1 Noxious Revival
1 Possibility Storm
1 Spreading Seas
Basically if you Gifts for Possibility Storm Snapcaster Mage Polymorph and Indomitable Creativity the "worst" pile you can end up with is Possibility Storm and one of our three sorceries, which will allow you to cast Enter the Infinite and win through casting repeated Beacon of Destruction for 1-mana or less each time.