I've been reading the forums for a bit and it seemed to me like casters were close to irrelevant for the longest time due to poor balancing of primarily melee weapons and long casting times of spells. That it was simply not worth casting spells on something like a cipher rather than keeping auto-attacks and using soul annihilation (on soul blade).

 

Has this changed at all? Are casters viable now?

Casters have always been viable, just nerfed compared to the first game (For good reason imo). Unless you plan to get through the game with very little aoe CC or aoe buffs, then you’re going to need a caster. You can use items and scrolls too for a short time, but those run out. Caster buddies are always there for ya, through good times and bad times. Wizards and priests also get access to some really great spells down in their tree. And the spells effects look great in the upgraded engine.