Stoicism really is aiming to make you Invulnerable in a way if you were able to do the right thing no matter the external you are Superman or Superwoman or scrappy do you can't be hurt? That's what the Stoics are trying to get through to us that we cannot be hurt by anyone but ourselves. The development of a virtuous character is still in your control as an example I hope is taken well if I step in front of someone in an effort to protect them and someone says move or I'll shoot you too My decision that follows is controlled not at all by the individual threatening me to get to that person else my decision rests only with me.