In my short playtesting with it I made my opponent discard a planeswalker that killed me in the previous game
Universal Dimensions: Pocket Dimensions: 2.6" x 3.6"(67mm x 92mm)

Cait Sith, Fortune Teller Capricious Sliver Case of the Burning Masks Caves of Chaos Adventurer Chandra, Flameshaper Charforger Chase Stein, Runaway Cleon, Merry Champion Commander Sofia Daguerre Compleated Conjurer Cori Mountain Monastery Count on Luck Court of Locthwain Crimson Caravaneer Crimson Operative Cunning Rhetoric Daredevil, Man Without Fear Dark-Dweller Oracle Dogmeat, Ever Loyal Duchess, Wayward Tavernkeep Elemental Mascot Elkin Bottle Emberheart Challenger Embodiment of Flame Endrider Spikespitter Equilibrium Adept Experimental Synthesizer Fire-Brained Scheme Fireglass Mentor Fires of Mount Doom Furious Rise Galvanic Relay Geistflame Reservoir Ghost-Spider Gila Courser Gloria, the Great Armorer Goblin Researcher Grotag Night-Runner Gwen Stacy Harnesser of Storms Hedron Detonator Heroes' Hangout Hidetsugu, Devouring Chaos Hotel of Fears Intet, the Dreamer Inti, Seneschal of the Sun Irascible Wolverine Ire Shaman Jaya, Fiery Negotiator Junk Jet Junktown Kami of Celebration Kellan, Planar Trailblazer Kulrath Zealot Laelia, the Blade Reforged Lightning, Security Sergeant Magmatic Channeler Mind's Desire Mishra's Research Desk

Usually, Standard is a format where there aren't many modifiers like cantrips or MDFCs, so these numbers won't vary as much across seasons
Instead theyre randomly selected from the previous 5 expansions: Rise of the Floodborn, Into the Inklands, Ursulas Return, Shimmering Skies, and Azurite Sea