From Dark and Darker Wiki
In many ways, this is the best boss in the game. The effects and atmosphere are impressive, and each attack is logical and avoidable. However, there are significant issues that detract from the experience.
At times, you only land one hit just to have the boss enter four separate invulnerability phases, each lasting way to long where you can't inflict any damage. I believe the locust attack should be shortened; it's frustrating to spend so much time simply avoiding it while watching it become invulnerable, especially if it occurs multiple times during a fight.
Additionally, the hide attack charge should be adjusted to prevent it from ending while the boss is partially embedded in a wall, causing her next shots to pass through the wall, and being harder to see where you need to avoid. The pull mechanic is also inconsistent, sometimes missing when you're standing still and other times hitting when it shouldn't.
My biggest complaint is the final phase, which involves a minute of walking in a circle while waiting for the boss to shoot about 14 shots. While the boss is killable with any class, not having a bard in your party makes it significantly more challenging to kill and have enough time to loot the rooms.