Aether Trap

If an opponent got 6 or more {e} this turn, you
may sacrifice an artifact and pay {u} instead of paying Aether Trap's mana cost.
Exile target nonland permanent. You may cast an artifact with converted mana cost 3 or less without paying its mana cost until end of turn
and as if it had flash. Untap that artifact when it enters the battlefield.
"Uh, Nissa?"