Armour of Light is not restricted to wanderers but is mostly used by them. It is rather a skill than a right.
If you are able to invoke your Magical Personality (regardless of your density of origin) you are able to create your own armour of light. Not many can invoke Magical Personality even among wanderers but the ones they can they do use the armour of light if they want to. Don for example in the last part of his life was not able to use his armour of light which served him well up to that point. If before incarnation you decided you do not want to be able to use the armour of light that will not be available to you even if you invoke your Magical Personality.
As long you are in your physical body, your free will will prevent any STS from imprisoning you, even though the STS can end your incarnation at any time if not protected by the armour of light. But by ending your incarnation an STS will lose any hope from winning you over so they will not end lives because this usually increase the polarity of the victim without having any benefit for the STS.
In Carla's case ending incarnation was considered only because of the impact her work had on the rest of us.
If you are able to invoke your Magical Personality (regardless of your density of origin) you are able to create your own armour of light. Not many can invoke Magical Personality even among wanderers but the ones they can they do use the armour of light if they want to. Don for example in the last part of his life was not able to use his armour of light which served him well up to that point. If before incarnation you decided you do not want to be able to use the armour of light that will not be available to you even if you invoke your Magical Personality.
As long you are in your physical body, your free will will prevent any STS from imprisoning you, even though the STS can end your incarnation at any time if not protected by the armour of light. But by ending your incarnation an STS will lose any hope from winning you over so they will not end lives because this usually increase the polarity of the victim without having any benefit for the STS.
In Carla's case ending incarnation was considered only because of the impact her work had on the rest of us.