Yueying

Yue Ying is the wife of Shu strategist Zhuge Liang. Despite her beauty, she spread rumors to the contrary in the hopes of attracting a husband who appreciated her intellect. Zhuge Liang heard of her wisdom, and sought her out. She invented Shu's juggernauts and wooden oxen.

10th Weapon Requirements
First, you must take out Zhu Rong in a duel. Second, make Ahui Nan and Dong Tu defect by defeating Yong Kai and his officers. Third, trigger the fire attack against Wu Tugu. Finally, defeat Meng Huo seven times throughout the battle.
 * Ultimate Weapon: Oblivion
 * Power: 53
 * How to get it: Nanman Campaign

11th Weapon Requirements
Basically all you have to do is defeat all the enemy officers, make sure the juggernauts are not defeated (one or two is ok), and after defeating Guan Yu, the level 11 weapon message will pop up.
 * Weapon: Nether Realm
 * Power: 60
 * How to get: Xu Chang

4th Weapon Requirements
Oblivion Base Attack: 36; Weight: Medium Stats: Defense +17, Life +16, Charge +15, Horse +15, Bow +16 Stage: Battle of Wu Zhang Plains (Shu) Location: South of Zhen Ji’s position, where there should have been catapults. Requirements: Eliminate Deng Ai before he sets up the catapults.