My DragonNestPatcherGUI patcher is still working fine (link in my previous post). Multiclient is working fine, all you need to do is create a shortcut to DragonNest.exe. Currently it is:
"C:\Games\Dragon Nest\DragonNest.exe" /ip:22.214.171.124;126.96.36.199;188.8.131.52 /port:14301;14301;14301 /Lver:2 /use_packing
Replace the path to DragonNest.exe with your path.
The parameters change some times, so you will need to update those when they do.