I have already decided to teach it Earthquake, Extrasensory, and Fissure.
Use U-Turn and get rid of Fissure for Knock Off or Rock Slide and replace Extrasensory with Stealth Rock or Rock Slide
Use U-Turn. It has better damage and gives you a good escape route. Also drop Fissure and grab a rock or fighting type move (two that Landorus learns naturally are Hammer Arm and Rock Slide). You need coverage against Ice types.