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 livrary 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.)