I managed to find out a bit more about the MMOSTG game Valkyrie Sky, which appears to be more aptly named Valklied Saga. It's currently related to the Hangame network, which is (if I understand correctly) a kind of online distribution service. There are tons more screenshots here and here, but you need to install some of Hangame's active-X plugins to get on their site.

For those brave enough to poke around their site, or who can understand Korean, there is a large button to "start game", but it redirects you to a login page, which I assume is Hangame's main server. If anyone can get this to work, let me know how it plays!

Valklied Saga main page.