You don't really need IEE for anything yet because the gains will be so small. I wouldn't invest in a buff spell until I had a skill capped out first. Also, Callidor's Tempest does Fire and Aether damage, so the gains from IEE aren't very good for this particular spell. You also took the transmuter for Callidor's Tempest which turns it more into a CC ability rather than a damage one. If you want to continue using this spell then you could respec to something like this
http://grimcalc.com/build/cGIk4g
Capped out Callidor's Tempest for damage, Olexra's Flash Freeze + Absolute Zero to act as CC and debuff enemies so you do more damage (-fire and phys res both benefit you with Callidor's Tempest). I also capped out Inner Focus as it is one of the best passive abilities in the game. No matter what kind of character you make, you cap Inner Focus if you have Arcanist. It's so good. From the Nightblade side I invested more points into Pneumatic Burst for survi and an increase in DPS as it gives +total speed%. Maiven's Sphere is ok, but I don't consider it a necessity anymore.
Some thoughts about this build: Callidor's Tempest is a tricky ability that confuses people, which is why most people avoid using it and think it's crap (it's not great, but it has its uses with the right build, which most people don't do). I wouldn't necessarily use it with this build. It works best for Soldier + Arcanist tank hybrid characters. It does 40% weapon damage and is inteded for people who want to do melee fire / aether damage, either with a 2h or sword and board.