When I was back in Seminary School... Okay, I attended a school run by a brotherhood of Marianist Priests...and of course there was the discussions on morality, sin and evil.
Morality: From the Latin, mores or "normal". Morality is the moving goalpost we call normally acceptable social behavior. Morality isn't about deep philosophical matters, but usual, day to day living...
Sin: When you have a list of laws or rules of behavior and inadvertently violate one of them, it is a sin. It doesn't matter who makes the laws, it is agreeing to adhere to those laws and breaking them by accident or without thought which constitutes sin.
Evil: When you have a list of laws or rules of behavior and consciously violate one or more of them, it is evil. Laws exist for a reason, mostly to facilitate a stable society to benefit people in general so the commission of evil does intentional harm to society in general. The thing is, you have to recognize those laws, no matter their origin, before you choose to violate them. You cannot be evil by accident, it has to be fully intentional...So when I do something, I am evil. Sinners are such wusses.
The above being said, people who don't hold themselves to the same laws may also not have the same morality as you. Slavery may be considered a form of charity that allows somebody living in abject poverty to lift themselves to a higher living standard. The Egyptian Mamluks were slaves and soldiers who were proud of their status.
The morals of society 200 years ago are very different compared to today. What may have been good then may be abhorrent today and vice versa. On my family's Chinese side, my Aunt, Lai Fong, walked with a limp because when she was a little girl, her feet were bound to keep her from running away from home, as girls in China sometimes did due to brutal conditions. Her father was a wealthy warlord and an rich Chinese American paid a lot of money to marry her. That was morality in 1920s China. Things got worse under the Japanese and even more worse under Mao, all due to the ever shifting goal posts on morality, especially when that morality is imposed, as imposed morality like forced charity, isn't real.
But what if your morality is under threat of say, an eternity of torture and not actually voluntary? Then I'd say that morality isn't real, either.
I then brought up this: The First Commandment: "You shall have no other gods before Me"
Most people didn't realize this: 1) The Ten Commandments were written solely for the Hebrews. 2) It is an admission that there are other gods to worship. It doesn't say, "I'm the only one" or "There are no other gods" but "You shall have no other gods before Me". It doesn't even say, "You shall have no other gods at all"... Just sayin'.
Brother Becker gave me such a look...
So...in summation, when a game tosses terms like "evil" and "good" around, I don't look at it in a religious context other than from the point of general morality, which may or may not be influenced by the local religion.
Doing things that benefit society in general: Good
Causing disruption to the stability of daily life: Evil.
Me, I've been a Taoist since I was 12 years old.