the boss does not exist, it is an april fool's joke from nexon and also internally the name was taken for a character in advanced so, someone in the nexon department wanted to add extra importance to their in game name as people will remember the april fool's reference... soo selfish.
April Fool us all Nexon with this Boss!!
And when our character dies, just warp us back to the log in screen
( character intact tho )
I'd just try uninstalling and reinstalling Nexon Launcher.
That's what I do whenever it starts buggin around.
Though, I've never had your problem, so sorry if this doesn't help. ;;