Prince Dastan of the Sands

When a player sacrifices a permanent, exile the
top card of your library with four sand counters
on it. (Remove one sand counter from each
card at the beginning of each upkeep)
You may play lands and cast spells without
a sand counter exiled this way without paying
their mana cost.
"All the pain in the world will not help you find
something that does not exist."