Humans genuinely have both Good impulses and Evil impulses.
What makes things tricky is, the Evil impulses come from a sense of justice, as if the other being harmed deserves to be harmed. It is often in hindsight that people realize that they themselves were being the villains, because, at the time, it felt "right" to inflict injury.
It takes effort to discern the most ethical behavior. Sometimes one must defend oneself or someone else.
Genuinely, humans have a Good side. I feel the Good side wins out more often than not.