Even in regular Diablo..

With a mage, if you are playing hell/hell it is very hard unless you are lvl 40+ All the Azures and knights, prevent you from casting magic, lots of guys are immune to fire and lightning, and many mages rely on Fireball and Chain lightning. Whenever i co-op, I use my warrior. My mage i co-op with when i am with other mages. I started abysmal with a mage because i knew it would be easy. i wanted to get a feel of the game before i start my rogue, (very hard)