use the thm spells banish and scourge don't waste your time with conjurer stuff unless you know enemy weakness and even then its not worth the effort. Banish 1 and scourge 1 will out damage almost anything over time because almost nothing resist them/you lower the enemy elemental resistance when casted on them, and also tier 2 spells only do maybe 100 more damage than tier 1 its not worth the mp/per cast and recast.

One thing i will say its that tier 2 get buffed a lot when you use the skill: profundity, but its a big hassle to look up enemy weakness only to find out it only does maybe 50 more damage than banish and scourge spam and not worry about what is weak to who. It sucks its this way still till this day but if you test them out you will see what i mean.