Rain of Riches is a rare Enchantment card from Magic Online Promos (PRM), collector number 99911.
When this enchantment enters, 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.)