Play Gan Ning's Legend under the expert difficulty setting. Kill Li Dian immediately. Close the bottom left gate. Kill Yue Jin before he regroups his men. This happens at about eight minutes remaining. Keep killing until Cao Xiu ambushes. Try to have about 90 kills. This will bring up the "Damage has been dealt to Wei" message a second time. Cao Xiu arrives at about 4:25 remaining. Kill him immediately. Keep killing until Zhang Liao appears. He will appear at about 2:30 remaining. You will get a message to find an exit. Do not do this yet. Keep killing until reaching about 140 to 150 kills. You will get a third "Damage has been dealt to Wei" message and the weapon acquired message. You will have little time to find the exit. Save the game just in case you cannot find the exit fast enough. Finish the stage to get Gan Ning's level 11 weapon, Leviathan. Its added effects are level 20 Speed Scroll, level 11 Horned Helm, level 16 Seven Star Sash, and level 19 Herbal Remedy