If Mirror of Possibilities is in your opening hand, you may begin the game with it on the battlefield. If you do, each player exiles a random card from their library face-up. For as long as Mirror of Possibilities is on the battlefield, those cards can be played as if they were in their owner's hand.

Artifactcycling {4} ({4}, Discard this card: Search your library for an artifact card, reveal it, put it into your hand, then shuffle.)