To get the fourth weapon of any character, get
1000 KO's on an Empire mode stage. You must have
got the 4th tech level (301-400xp) in the chosen
officers weapon format, ie - Zhang Liao has a
spear type weapon, raise spearsmith to level 4.
Then, choose any location on the empire map
(must be empire mode, remember), and get 500
KO's plus. After the stage, you will receive the