A lot of fighting games have been coming to Steam this past year, including Guilty Gear XX. It seems as if publisher H2 Interactive isn't done with the series yet, as Guilty Gear Xrd has been listed on the Korean Game Rating database for PC.
This is odd timing, as the follow-up, Revelator, was just confirmed for an international release this week. This listing is for Sign, which is the base game. We've reached out for comment, but H2 will likely be sharing the news at some point in the near future.