I got your point here since I own some private businesses, however " Gravity " is milking their Ragnarok game since 2002 and they have abandon Rose after alot of dupe happened around 2003-2005.
But what if the developers abandon Rose theme and they started to use unreal engine to create similar game to Rose without breaching the legal terms or copy righting, What I mean here is to keep the core of game style, and redesign everything else?