oh wait. i did take down that spectator. that was like my first encounter in the underdark after i did the puzzle thing and unlocked the waypoint and the front gate. i veered off to the side first and thats where i had to fight it.
i battered it down with laezel and made short work of it. i even got an achievement during that battle for performing 5 actions in one turn. i snuck up on it and surprised it with a range attack from a bow, then i killed its statue buddy with laezel and it gave me another free turn, and then i used action surge and got an extra turn and then i used a bonus to slap it down some more. i'm not sure how it all went down but by the time laezel gave it a good thrashing my pally was able to make short work of it with a couple smites.
i don't even think it managed to get a lick in on my party.