Question about Blightstormers in Tower of Treachery

I’m finding it increasingly difficult to find them and kill the blasted things. I’ve seen them casting through the walls of the end event and wipe our group because no one could find him afterwards. We couldn’t really tag him because he was through the wall. Sometimes they’ll teleport themselves into the “prep room” that we were previously in and yes technically we have a LoS to them but sometimes they’re all the way in the back of the room so i’m trying to shoot through a mob, trying to run away from the wheel of death, shoot through the palisade and hit the stormer in the back room next to one of the kegs. I feel like that’s a little unnecessary for them to be able to spawn in there, but I also feel like there’s probably some skill aspect that i’m missing here.