I have seen this too many times in arena and I want to help out my fellow DQ arena mates.
If your build doesn’t have the regen to continuously cast don’t set your AI to stand back and cast, because I will just wait for you to run out of mana or health and run in and finish you off.
If your build is leech based, don’t set your AI to cast out of range because you will not be leeching anything from the air.
GLHF!