This mmo like RO and it's already closed.
A few years ago, I remembered playing this game in 2008, but it was already closed.
For fun, I decided to try to "run" this game. So, I found the game client and do some work for investigate game packets for login. Result on the attachment.
So, If someone want to do server for this game I can investigate all game packets, and do game client data extraction.
All what I already done(some packets description, simple server response emulator, extraction tools) is on this page: https://github.com/Marisa-Chan/Xen-O-Proto
Git repository also has utils for some data extraction, like this: https://imgur.com/a/NC1UDLH
And also I made torrent for found game clients.
P.S. If you are still has newer game client - please give it to me - I will add it to torrent.