Rain of Riches

When Rain of Riches enters the battlefield,
create two Treasure tokens.

The first spell you cast each turn that mana from a Treasure was spent to cast has cascade. (When you
cast the spell, exile cards from the top of your library
until you exile a nonland card that costs less. You
may cast it without paying its mana cost. Put the
exiled cards on the bottom in a random order.)