Phyrlesa, the White Flame

At the beginning of each players end step, that
player gains energy counters equal to the number
of permanents he or she controls. Then, Phyrlesa
the White Flame deals damage to that player
equal to the number of energy counters he or she
owns.
Once each turn, you may pay X energy counters:
Put a card in your hand from your graveyard or library with converted mana cost equal to X.
Then, Shuffle your library. You may use this
ability from the graveyard.