The availability of hard CC and how easy it is to chain CC targets should be looked at; I just completed the final encounter with three other friends in co-op and the four of us playing were able to tackle it in one go without any difficulty what-so-ever.
We chain CC'd Alexander so he was unable to act the entire fight, and each other enemy wasn't a problem to CC and then kill, either. When the void creature showed up we had already dealt with every other enemy, and it alone didn't put out enough damage or CC to threaten us at all.
I'm not sure how this could be addressed, however... The removal of strong CC options would currently make the game way too difficult, as it currently feels like locking down specific targets is necessary to survive an encounter. For most of our fights we didn't choose to chain CC enemies because we wanted to cheat the game out of a fair fight, but rather it felt as though if we didn't abuse our CC we would die within the round (that witch with the purging wand says hello). It creates this odd split where an encounter is either too difficult without CC or too easy with CC.
Something that may be worth more thought would be how soft CCs like Cripple and Blind can only be applied when the target is also vulnerable to hard CCs. From my experience, hard CC is much more desirable than soft CC; the only circumstance in which I would take cripple over knockdown is when the target in question is immune to knockdown. Additionally, it is difficult to gauge the effectiveness of a status effect like cripple since players are unable to see AP thresholds and costs for NPC actions. This can lead to it feeling a lot less impactful than it actually is.
