mtg amonkhet card list Magic The Gathering The Single Uncommon Labyrinth Guardian AKH-60 An individual card from the Magic Magic Duels Adds the Amonkhet

That leaves us with 3 good learn cards and another 3 or so that are potentially enough for cube

Cogmentor Contraption Cannon Curious Killbot Entirely Normal Armchair Everythingamajig Gnome-Made|Engine Handy Dandy Clone Machine Kindslaver Krarks Other Thumb Labro|Bot Lobe Lobber Mad Science Fair Project Modular Monstrosity Proper Laboratory Attire Robo- Split Screen Staff of the Letter Magus Stamp of Approval Steam-Powered Steel Squirrel Sword of Dungeons & Dragons Voracious|Vacuum Accessories to Murder Applied Aeronautics Arms Depot Auto-Key Bee-Bee Gun Boomflinger Buzz Buggy Deadly Poison Sampler Dictation Quillograph Dispatch Dispensary Division Table Dogsnail Engine Dual Doomsuits Duplication Device Faerie Aerie Genetic Recombinator Gift Horse Gnomeball Machine Goblin Slingshot Guest List Hard Hat Area Head Banger Hypnotic Swirly Disc Inflation Station Insufferable Syphon Jamming Device Lackey Recycler Mandatory Friendship Shackles Neural Network Oaken Power Suit Optical Optimizer Pet Project Quick-Stick Lick Trick Rapid Prototyper Record Store Refibrillator Sap Sucker Sundering Fork Targeting Rocket Thud-for-Duds Top-Secret Tunnel Tread Mill Turbo-Thwacking Auto-Hammer Twiddlestick Charger Widget Contraption LAND Secret Base Watermarket Plains Island Swamp Mountain Forest WHITE | BLUE | BLACK | RED | GREEN MULTICOLORED | ARTIFACT | LAND | ALL CARDS

It had more uses with faeries back during the Lorwyn era, but the synergy is tis there for anyone who can exploit it

A card must already be exerted in order to be challenged, meaning you cant challenge characters played on your opponents last turn

This can even do work in Standard with cards like Hylderblade or Dark Knight's Greatsword

3 Emrakul, The Aeons Torn For the massive cost of fifteen mana, Emrakul, the Aeons Torn is often referred to as the strongest Eldrazi to ever see print and is the only creature on this list