Been thinking about bringing in an outside friend to role play or at least control the the boss for the up coming battle. Being able to stage a fight where the boss honestly has no idea of what the players will do or what their skills are but has absolutely no hesitation about trying to kill them seems like it would be pretty cool. And know matter how much you try as a DM you can't not know things and even in a grim dark game like we're playing it does really suck to kill your players so there's always the desire to pull your punches even if you don't do it. Having a boss that not only goes straight for the throat but is also played by someone who thinks differently than the rest of the encounters my players are used to seems like it would make it truly unique fight.