When one experiences that ultimate surge of pleasure and excitement and cosmic feeling that comes from tapping into one of life's many vital wells, however one does it, one can't forget the experience. One seeks the repetition of such an experience the rest of one's life. One experiences it through wielding power, or engaging in pleasurable acts or contemplations; in the end it is a property of the body (every body should be wired for it) that is activated in some way through an external source or a mode of behavior or ritual.
The archetypal Saint and Martyr seeks to share the experience or ferry as much people as possible to a point at which they can experience it themselves. The archetypal Monster seeks to keep such an experience all to him or herself. One arrives at a binary choice and makes one's choice in accordance with one's character and propensities.
The archetypal symbol takes its meaning from social relations. Saints share power and the experience of the Good, and so others benefit and even those observing the spectacle remark that such a vessel is Good. A Monster on the other hand is the sole benefactor of said power and experience of the good, so all who witness such an event have no choice but to declare the Monster "Bad," or "Evil," as such a vessel is observed to take the Good from others to benefit him or herself. The actual Monster sees him or herself as the Good and source of all that is just, but that experience is severely limited to him or herself and maybe a smattering of authoritarian followers which get to share in some of that good, but ultimately fear and loathe the Monster.
Judgment by observers can be split either way, according to ideology and emotional disposition. However if someone is personally wronged (or benefited) they usually have no choice but to assign the Bad (or Good) accordingly.
So what will it be then? Eternal struggle for the experience of this Good and the consequent eternal divisions and antagonisms? Or a communal sharing of the Good and its subsequent harmonizing effects?