I am going to add my input for mage here.
Might as well make this thread useful.

Mages have the cheapest gears but have the weakest potential out of the other two classes.

I personally use these skills:
(support / tanky / cc)
- Fireball
- Gale
- Curse
- Shield

( offensive / support / cc)
- Fireball
- ice
-curse
- gale

The latter one works for me better but you need to be cautious and needs some decent amount of pots because you will be spamming your skills a lot.

I have 5.2k dmg without boost and 7.8k with boost.
Armour is 5k (alright)
Health 10k (decent)