Known issue: Empress Cygnus bosses

Actually I have. Was a professional programmer for about 25 years.
There is indeed always one more bug.
But it's not normally this serious, nor this similar to previously patched bugs. Not if you test your code, and not if you employ the right people.
How come the hackers are always able to come up with these things within days or even hours of the version-up, and under black-box conditions at that, while Nexon's own people can't imagine what is possible while having the code open to them?

Hackers only do one thing, Find a way to screw over the game.

Nexon on the other hands got their hands full with localization,patching errors,dealing with the hackers, etc etc.