And yes, balance. I'm not talking about physical classes (I haven't tried it - I don't know). But the arcanist is just a mind blowing machine.
Everything rests on two significant facts - firstly, you have a spell that ignores ANY RESISTANCE of the enemy (and this is really so, you only need level 12), and secondly, an invulnerability spell for 4-5 moves (shadow bound, if correct remember).
Having collected the appropriate gear (mana regen and spell damage), you can simply demolish any creature.
I took down Queen Marie in the first fight as if nothing had happened♂. Of course, according to the descriptions of the talent tree, I should be like that, but still the spell system needs to be worked out.
Alternatively, just give some spells a cooldown when you can't use them - this would force players to approach the game differently. The role of the same consumables would increase, for battle it would be necessary to use tactics for each stage of the "boss"