Discover X exiles cards from the top of your library until you reveal a nonland card with mana value X or less. You can cast that card without paying its mana cost or put it into your hand, with the remaining exiled cards going onto the bottom of your library.
Pantlaza, Sun-Favored can repeatedly reward large Dinosaurs with discover, while Quintorius Kand turns casting cards via discover or other effects from exile into additional damage and life gain.
