If you don't reveal an Equipment card, or if the exchange can't be completed (such as if Arcanum Things is no longer on the battlefield, you don't own Arcanum Things, or the new Equipment can't be attached to the creature Arcanum Things is attached to), nothing happens
Sadly, while Optimus Prime, Hero has a good chance of catching players off guard, he isnt the cheapest MTG card to pick up
The flexibility of exiling key permanents such as Amulet of Vigor or Aether Vial is extremely relevant in a format as diverse as Modern, and many decks are even opting to splash an additional color by adding off-color Shocklands or Tri-color (Triomes) lands to their mana base, so they pay an additional color for the converge mechanic on Prismatic Ending
It takes on a slightly different play style, but the added life gain from Zulaport Cutthroat will help keep you in the game and the other additions in Black add a board wipe, reanimation, and Tutor
Premium Pages Protect cards from damage caused by acidic materials
