(doesn't work for everybody!)
#1 install the chinese Aion (for me the EU Aion [first post] didn't work)
#2 run the game through the .exe on your desktop
#3 let the game patch
#4 try to start up aion after gameguard patched
#5 if you have no error you are able to play the chinese game
#6 download
#7 go into your aion folder and copy the file into l10n (you need the chs files too, don't delete them!)
#8 change your regional language (control panel / systemsteuerung)
#9 run aion through the .exe on your desktop
#10 should these steps helped you, thank .envy !