Asclepius, Dragon Mage

-4: Go through your library and find either a white or green Elder Dragon and put it in your hand.
+1: For every turn an Elder Dragon receives no damage Asclepius gains one loyalty. (The Elder Dragon can be any color and must be on the battlefield)
X: Sacrifice Asclepius to bring back any Elder Dragon from the graveyard and put it back into the battlefield with a +1/+1 counter on it.