Recursive Spellcasting

(You may cast a legendary sorcery only if you control
a legendary creature or planeswalker.)
Other spells you cast this turn have cascade.
Exile cards from the top of your library until
you reveal a nonland card. You may cast it
without paying its mana cost. Put the rest of the
cards on the bottom of your library in a random
order. Exile Recursive Spellcasting.