I am sorry if I upset you by calling Shiva evil. I have a theory that gods are divided into good, indifferent, and evil governing sattvic, rajasic and tamasic gunas respectively. All our thoughts and beliefs are derived from gods in our subconscious. You may not like the word evil but what I mean by that is that if you are evil-minded person who is prone to doing bad things from svabhava (nature) you will be attracted to a evil god in your guna consciousness no matter what name you give that god. And since Brahma is sattvic, and Vishnu is rajasic, that only leaves Shiva to be the Trimurti's evil god. Sorry if this is unpalatable to some.