If an Evie is coming after you solo, gather around with enemies to avoid being out-flanked. Also, expect an Evie after ice-block to teleport immediately.
If Evie uses Wormhole, try to pick up on any trends. Does she always warp back? Does she warp after using Soar? Does she like to warp up in the air? Use this information to predict her movements and take her down.
You must be unpredictable; and accurate with ice staff. You need to always be doing something with her. Looking around for enemies and just be a complete nuisance.She takes time, practice, and patience to play her well. High skill, High reward!