How do you get Cao Rens level 11 weapon in Dynasty Warriors 4 Extreme Legends?

Meet with Niu Jing only after Niu Jin reaches 8 star morale. Defeat Han Dang and Gan Ning after meeting with Niu Jin. Defeat the 2 ambush troop generals (Zhou Tai, Zhou Yu) after they appear. All the while keeping Niu Jin's HP as high as possible. Achieve at least 250 KO Count. Defeat enemy soldiers and Niu Jin's morale will rise. Eliminating enemy entry points will also raise Niu Jing's morale. If you defeat both Han Dang and Gan Ning, you will meet with Niu Jin automatically. It is acceptable if you defeat one of the two before meeting with Niu Jin. After meeting with Niu Jin, there will be a Precious Item Report, the Bodyguard Learned Lesson. The 250 KO Count seems to be the minimum required for unlocking the weapon. If Niu Jin loses more HP, or if the battle took longer time, the KO Count will also have to be higher to compensate for the less than acceptable performance. I suggest equipping the Morale Drum if you have it, it does help. Do this on Expert