Dynasty Warriors 6 Unlocking Guide
2008 February 23 
9 characters are optional from the beginning while over 30 others can be recruited later, by finishing Musou modes with various kingdoms / officers and also by completing certain tasks within battle.
The complete DW6 Unlocking List also points out which of those characters have musou modes (17 characters do).
Feel free to check out the Dynasty Warriors 6 Walkthrough Index
Thanks…
Comment by Martin—June 16, 2008 @ 10:22 pm
The only thing I can think of is you are doing the wrong level? It has to be Battle of He Fei Wu Side (some people get confused and think it’s battle of He Fei Castle). Cao Ren should be protecting the northwest castle and Xu Huang the northeast castle (but I think you just need to defeat Cao Ren, and then Xu Zhu in the center who is roaming around).
Hopefully that works on He Fei Wu Side for you, if not who else is in the northwest castle there?
Comment by Lord Yuan Shu—June 18, 2008 @ 12:19 pm
Thanks for your answers. I think you are right. I was doing Lu Xun musou mode but apparently the scenario is Battle of He Fei castle and not He Fei Wu side. I will see how do i get on to the He Fei Wu side battle.
Comment by Martin—June 30, 2008 @ 2:58 am
I change the correct level, the correct force, but he isn’t unlocked
Can you help me ?
Comment by Vitor—November 2, 2008 @ 1:37 pm
Comment by Lord Yuan Shu—November 11, 2008 @ 2:14 pm