Metaion, the Timelord (PGL2-EN034)

Cannot be Special Summoned from the Deck. If you control no monsters, you can Normal Summon this card without Tributing. This card cannot be destroyed by battle or by card effects. You take no Battle Damage from battles involving this face-up Attack Position card. At the end of the Battle Phase, if this card attacked or was attacked: Return all other monsters on the field to the hand, and inflict 300 damage to your opponent for each card returned. During your Standby Phase: Shuffle this card into the Deck (even if face-down).