Gandalf the Grey

0: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
+1: Sacrifice a Clue. If you do, draw a card and creatures you control gain "{t}: This creature explores" until end of turn.
-X: Gandalf the Grey deals X damage to any target. If Gandalf the Grey dies this turn, return him to the battlefield transformed under your control.