Imperishable Operative

Imperishable Operative can't block.
When Imperishable Operative enters the battlefield, you get {e} (an energy counter).
Revolt - At the beginning of each end step, if a permanent you controlled other than Imperishable Operative left the battlefield this turn, you may pay {e}{e}. If you do, return Imperishable Operative from your graveyard to the battlefield.