The Kushluk Assassination Achievement
The Kushluk Assassination20
Kill Kushluk before 20 minutes have elapsed in the second Genghis Khan mission.The best way to complete this is simply to rush with your starting army. You will want to use one soldier to attack their tower and lure the Kara-Khitai away from their base, then rush through with the rest of your army to find and kill Kushluk. If he flees he will flee back to his town centre. You can prevent him fleeing, however, by attacking the wall to the south of where he is.
The following video has a good strategy at 8:55