After seeing Vader strike down Obi-Wan, Luke attacked recklessly until he heard the old Jedi Master’s voice warn, ‘Run Luke, Run!’
At any time, move Luke as a regular move (using landspeed for free) to a battle just initiated at an adjacent site. Luke is power +2 during that battle, unless Vader is present or adjacent to the battle site. OR You may cancel Vader’s Obsession.