Help on Facebreaker Build

I'm currently a level 32 with the 'Facebreaker Strapped Mitten' and I'm playing using dominating blow and minion instability. I have a few question.
-Leveling dominating blow?
-Using aura instead of blood magic so I can better support my minion?
-Getting reduced mana for my dominating blow or stack all 3 added damage to my dominating blow so my minions are stronger?

If anyone have any view or suggestion please feel free to comment. Thanks!