(I'm not fully sure but what I'd say is
Yes, they could take you to court if you break the Copyright Law, but as AeriaGames is only a licensed publisher, AeriaGames will not be able to take you there, they may only inform the Copyright holder. As the Copyright is at NEXON Korea Corporation, they will be able to take you to court due to copyright infringement(the question is: will they or won't they do that?). But if you just don't advertise on OS or on their site, you'll be fine. I personally never heared that the producer took a PServer to court for this though.