MISFIT Adventurers Because The System Made a Mistake?

In the world of Lavriehn, humanity and demons have been at war for centuries. Every fifteen years a new Demon Lord rises, bringing another age of bloodshed and despair. Seven heroes have fallen trying to end the cycle, and only two Demon Lords have ever been defeated. The first was slain a hundred years ago by the legendary Hero Sol. The second fell twelve years ago to an unlikely knight named Bones, a man who was never meant to become a hero. Now peace is beginning to fade once again. In Lavriehn, every person is granted a class by the System upon reaching adulthood. Warriors become swordsmen, healers become clerics, and talented fighters become knights. At least... thats how its supposed to work.