Lord of the Flies
Simon is calm, wise, caring, and brave. He's the one who realizes that the beast is "only us" (5.195), and he's the one who tells the boys to face it—because what else can they do? He even tries to get them to understand that the beast is just a dead man in a parachute.
Sadly, Simon's success as a mentor comes to a brutal end when his pupils decide to kill him rather than listen to him.