Warhammer: Chaosbane - Chaos 10 clear with Mage build

For passives:

Quaysh Shield (Superior) - Seems like a no brainer here, health regen, and damage.
Arcane Binding (Mastered) - 1 attack with phantom blade gets the fire + magic bonus with 1 hit.
Hero of the Desert: no brainer here
Aqshy Mastery (mastered) - fire damage and crit bonus for burning.
Aether Intelligence (mastered) - no brainer here
Counter Spell (superior) - Gives more damage than master blacksmith, but you can use that too.

Attack Skills:

Phantom Blade (heroic)
Step Between worlds (heroic)
Aether Vortex (mastered)
Aether Storm (mastered) - lightning bolts give you a 20% damage buff
Arcane Manifestation - Still good for a low level god spell.

Legendary Skill: Legendary Punishment - 100/100 50% chance enemies take 50% more damage for 5 secs.  Anything else is icing on the cake.  

God Tree: Refer to the video.