Fiery atomizer vs Voltaic tempest ?
I use gravitation vortex as second weapon, so voltaic makes a great combo.
But there are a few bad things, no nock back (sword), move is a bit unpredicable, can break things, hard to get UV... BUT deals more damage than fiery when there are lots of ennemys.
Fiery makes much more damage and i can get a good UV.
So what should i take?
Presumably you mean Ash of Agni vs. Voltaic Tempest. VT can do lots of damage if the enemies are packed tightly, but I think that AoA does more damage against a loose crowd. Of course, it doesn't inhibit the monsters' movements and attacks, which can be a bad thing or a good thing. They have equal knockback. Oh, you must have meant that shock hinders knockback? Yes.
They're both great, so you should get both eventually. I think that VT is a higher priority, because it can really help you survive against crowds of devilites and that kind of thing.