Conquer is a bit of negative word, and it also implies finality. If we want to avoid creating the impression that Luke’s legend has assured the galaxy victory, we should avoid anything that suggests finality.
So among these options:
“Legends can push back fear.”
“Legends give courage against fear.”
“Legends give courage in the face of fear.”
“Legends inspire action in the face of fear.”
“Legends inspire action, even in fear.”