Xolatoyak Observatory

This land enters with 3 storage counters on it. You may choose not to untap this land on your untap step, if you do, add a storage counter.

{t}: Remove a storage counter, and exile a creature you control. Add an amount of mana equal to the exiled creatures converted mana cost. The colors must be of the same kind in that creature's mana cost. Return the exiled creature to its owners control at the beginning of the next end step.