Shilone, Keeper of the Vault

At the end of each of your phases, put a
+1/+1 counter on Shilone for each unspent mana in your mana pool.
Sacrifice Shilone, {t}: Add X {u}, {r}, or {g}, where X is the amount of +1/+1
counters on Shilone.
"I wonder what's in her vault."-Jace