If the society is evil, then is it surprising if it harbours a devil? But there is always an anomaly. Sometimes, in a city full of evil, an angel is born.
And what does evil do when an angel is born among them.
Like all good things, the angel would either be corrupted or be eradicated.
And then if the society is good, it is not surprising that even they lack many things, they live a happy life, and there is angels walking around
And just like in that other society, if a devil is born among the angels, either nurture would win against nature, or nature would take its course.
This has always been the case
Good always have to prove themselves yet evil get a pass.
But there is always more good people than bad and hence the evil hides.
When evil become the commonplace, then good people have to hide and evil is done in plain sight
Whether your world become evil or good, always depends on people. First one person, then two, then three.
