Hit me please! HIT ME MOAR!- Help & advice!

The plan is to make a shieldwielding-reflecing-damage scion.
I would like some help/advice with the following build!

The build-


The build is based on blocking and taking hits.
So the base skills will be Tempest shield,Moltenshell and Articarmor.
With the supportgems of cast when taking damage.

But all im looking for now is tips to improve the passive skilltree!