Have I ever encountered evil or dark spirits, the answer is No. Why do I think this is? I don't believe in evil spirits or right or wrong... as right and wrong are subjective judgements based on an individuals experiences they have learned through, parents, church, society and personal experience. What I may think is wrong may be totally acceptable to you.
What is outlawed in Canada may be totally acceptable in the middle east or vise versa. Nobody does anything because they think they are wrong... No we can justify anything ... once again it is one's perspective that makes something right or wrong.
If person believes in evil, the devil and a vengeful God ... let them, who are we to try to
convince them otherwise. I will tell you that when we cross over we experience every emotion we have created for another... so if you look at that as punishment then so be it... I see that as a natural law of cause and effect. Everything we do is energy and what goes out has to come back.
I hope I have answered your question.