Dynasty Warriors 3: 4th Weapon Guide - Zhang Jiao

This is a guide in order to obtain the 4th weapon for Zhang Jiao, in Dynasty Warriors 3.
Weapon Name: Volcano Staff
Base Attack: +37
Element: Fire (C5)
Other stats:
Musou Max: +72
Attack: +43
Reach: +27
Requirements:
Stage: The Yellow Turban Rebellion (Original Mode) - Yellow Turban Forces
Defeat Sun Jian and all his sub-officers, OR Cao Cao and all his sub-officers, OR Liu Bei and all his sub-officers. Weapon Box appears north of the castle, on the east side of the river near the Dim Sum.
Other notes:
You have 3 different ways of meeting the requirements, so choose whichever you prefer, or if you fail to get it from one of the main generals, you have 2 backup ways of getting the weapon instead. The hard part is not beating the officers, but ensuring that you are the one that gets the kills and not anyone else. Regardless of which general you use to get the 4th weapon, this will not be a difficult stage to manage at all, for you at least, the rest of the Yellow Turban forces will not last long at all.
The river does not freeze until Zhang Liang is defeated as normal, until then the only crossing point from the north is in the far west, near the gates there. This means you have to travel to the east side of the castle and head north to reach the 4th weapon, or climb the wall and jump over there if you prefer, but that leaves you with a long walk.