Blood Shaman of Chandra

Cascade (When you cast this 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 of your
library in a random order.)
As this spell's cascade trigger resolves, the exiled
cards remain in exile. You may play cards exiled
this way until the end of your next turn.
"Chance is the key."