Dix, Galactic Voyager

Dix, Galactic Voyager untaps each
untap step if you have {5}or more
instant or sorceries in exile.
{t}mill {5} cards from your library.
{u/b}{u/b} Copy target instant or sorcery from your graveyard for each
instant or sorcery casted this turn.
Exile the casted card after resolution.