Though being a hero or villain has little to do with it, one word that comes to mind is 'flaggelant'. Keep in mind that this word not only describes the act of self-punishment, but also describes the 'how' (by means of flogging/whipping).

Depending on context (ie. why does she punish herself), again without much incorporating the hero/villain concept, another applicable word may be'masochist'.

Though being a hero or villain has little to do with it, one word that comes to mind is 'flaggelant'. Keep in mind that this word not only describes the act of self-punishment, but also describes the 'how' (by means of flogging/whipping).

Depending on context (ie. why does she punish herself), again without much incorporating the hero/villain concept, another applicable word may be 'masochist'.

Sticking with the assumption that the self-punishment is religion or honor based, the "filling the role of both the hero and the villain" part might be better served with a phrase like 'filling the role of both judge and jury'.

Though being a hero or villain has little to do with it, one word that comes to mind is 'flaggelant'. Keep in mind though that this word not only describes the act of self-punishment, ie. penance, but also describes the 'how'.

Depending on context (ie. why does she punish herself), again without much incorporating the hero/villain concept, another applicable word may be'masochist'.

Though being a hero or villain has little to do with it, one word that comes to mind is 'flaggelant'. Keep in mind that this word not only describes the act of self-punishment, but also describes the 'how' (by means of flogging/whipping).

Depending on context (ie. why does she punish herself), again without much incorporating the hero/villain concept, another applicable word may be'masochist'.