If you are willing to go to 22. i have a build for you. I am also a tank mage (22) and i feel your pain :P

I have spent over 500 plat adjusting my build to perfection.

Here it goes

6Bom
6Bov
5heal
1drain
1ice
1fire
1light


IGN: Hahawaitwhat

Kills 2042 deaths 234