If you choose to pay the dash cost rather than the mana cost, you're still casting the spell. It goes on the stack and can be responded to and countered. You can cast a creature spell for its dash cost only when you otherwise could cast that creature spell. Most of the time, this means during your main phase when the stack is empty.
Ragavan, Nimble Pilferer
You must still follow all timing restrictions and pay all costs when casting the exiled card. If you exile a land card, you can't play that card.
You'll create a Treasure token even if that player has no cards left in their library to exile.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Simon Dominic
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
