Ethersworn Sphinx (MH2-195) - Modern Horizons 2

Affinity for artifacts (This spell costs less to cast for each artifact you control.)
Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card with lesser mana value. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)