Mirror-Mad Phantasm and Mirror of the Forebears on the battlefield.
"Spirit" chosen with Mirror of the Forebears.
({2} magic symbol) ({U} magic symbol) available.
Steps
Activate Mirror of the Forebears by paying ({1} magic symbol) , causing it to become a copy of Mirror-Mad Phantasm until end of turn.
Activate Mirror of the Forebears by paying ({1} magic symbol) ({U} magic symbol) , shuffling Mirror of the Forebears into your library and milling your entire library due to it not having a card named Mirror-Mad Phantasm in it.