A dream involving an evil atmosphere or evil spirits foretells that you will encounter obstacles to your current ambitions. You would be well-advised to consider a change of direction or plans.
To dream that someone or something is evil, signifies a repressed and/or forbidden aspect of yourself.
This part of yourself may be seeking recognition and acknowledgment.
Alternatively, evil in a dream may also be a reflection of your strong, negative emotions like hate, anger, etc.