First, let's define "evil" from a spiritual and psychological perspective.
"Evil" is what happens when someone is desperately unhappy and doesn't know how to become happy. They become self-centered and the things they do, they do in order to TRY to become happy.
Too often, though, we don't take charge of ourselves .. we just live our life on auto-pilot, blindly acting and reacting to whatever stimulus triggers a response in us.
Human beings are capable of SO much more than this unintentional, instinctive way of living.
So there are no evil people. Only unhappy people. Who don't take charge of themselves.
But everyone can learn to become happy ... it has nothing to do with what's going on in your outer life, and everything to do with what your unconscious attitudes are and how self-aware your are.
Now, as for astrology charts ....
What beings out the best or worst in a birth chart is the aspects, not the signs.
Harmonious aspects, such as sextiles and trines, bring out the positive side of the planet and the positive style of whatever sign the planet is in.
Discordant aspects, such as squares and oppositions, bring out the negative side of the planet and the negative style of whatever sign the planet is in.
Because all signs have both postiive and negative sides.
And everyone has at least one harmonious aspect in their chart and at least one discordant aspect too.
And since our birth chart is ONLY an influence on us, WE have the ability to rise above it and be self-determining. Our chart is only as much of an influence as WE let it be.
So, are some people born with an evil birth chart? No. Some charts ARE more difficult than others, but I have seen very negative charts where the person rose above it and mastered themselves and became happy. And other very-easy charts where the person never lifted a finger to become self-aware. It is not what we have to work with, but whether or not we work with it.
Yes, our background has a lot to do with it .. but since sociologists tell us that 97% of all families are dysfunctional to some extent, WE have to take responsibility for ourselves at some point and stop blaming our past for our shortcomings.
Can everybody be a good person if they want? Yes. But first they have to find out how to be happy so they aren't self-centered and selfish in their actions.
And often that IS the way to happiness.
Psychology has found that happier people are those who give and share with others.
And that the unhappier people are those who are self-centered.
So, we can deliberately turn our focus off or ourselves, and learn to care about others instead, if we want to be happy.
For instance, my sister volunteers every Monday evening to cook and serve food to the homeless at a homeless shelter in her city.
My daughter (an equestrian) volunteers once a week with an organization that pairs handicapped children up with horses, giving the kids a sense of power and connectedness through the bond they establish with the horse. She puts the child on the horse, and leads the horse around for an hour.
It's really important, for inner happiness, to care about others.
And this is how we overcome our inner unhappiness, which is the source of any "evil" actions that we do.