Instead of completing 11 stages to unlock Zhang He, on 'Battle of Guan Du - Wei Forces', burn down the supply depot Wu Chao. If Zhang He isn't defeated yet, he will defect and surrender to your side. At the end of the stage, he will be unlocked.
Diffrent Forces
The 3 original forces are Shu, Wu, and Wei. There are some unlockable forces aswell. To play with Lu Bu's force, beat the game with any original force. To play as the Namans force, beat the game with the shu force. To play as Dong Zhuo's force beat the game with Lu Bu's force.
Get Items
To get items that increase your characters skills is simple. When you defeat an officer they may leave one behind, instead of the usual Defense of attack ups.
Hint: Red Hare Saddle.
The Red hare is the fastest horse in Dynasty Warriors 4. But if you don't want this cheat, and prefer to just knock off Lu Bu and Guan Yu from it, I guess that's fine.
Well, go to the Battle of Xia Pi and choose Lu Bu's forces(required to beat Musou mode first) and DON'T KILL ANY OFFICERS UNTIL GUAN YU STEALS THE HORSE!! Then, kill Guan Yu and a message bar will appear saying 'A valuable item has been discovered' Go to where the Red Hare was originally and there will be a Red Box. Break it open and you will get the red hare saddle. After, finish the stage by killing Cao Cao.
Mutiple Red Hares
To get multiple red hares go to Free Mode, then Yi Ling, then to The Campagain for Jing under Liu Bei's forces. When you start; defeat Cao Ren, Liu Du, Jin Xuan, Zhao Fan, and Xiahou Yuan in any order (this will help you advance to Guan Yu without having to fight). When you are by Guan Yu wait until he gets knocked off the red hare, then steal it and ride it around for a couple of seconds. (Make sure you cannot see Guan Yu when facing any direction or this will not work.) Then go back to Guan Yu where you can see him and he will be on a second red hare. Wait until he gets knocked off the second one then steal it and ride it like before and there will be a third one when you see him again.
Obstacles
When dealing with magical obstacles; i.e.: boulders, floods, wind storms, kill the magician that made it to deactivate the obstacle. When it's military; i.e.: catapults, fire juggernauts, free-standing forts. Destroy it with your character attack.
Unlock Meng Huo and Zhu Rong
You must be in Musou mode. Defeat Meng Huo seven times throughout the stage. At least one defeat must be a duel. Also, duel and defeat Zhu Rong. Complete Musou mode and Meng Huo and Zhu Rong will be unlocked.
Unlock Opening Edit Function
To unlock this, unlock all 42 characters. Then, beat the game with one character from each force.
Unlock Wei Officers
Complete the following tasks in Wei musou mode to unlock the following characters.
Unlockable / How to Unlock
Cao Ren: Clear Chapter 3 in Wei musou mode.
Dian Wei: Clear Chapter 1 in Wei musou mode.
Sima Yi: Clear Chapter 4 in Wei musou mode.
Xu Chu: Clear Chapter 2 in Wei musou mode.
Xu Huang: Clear Chapter 1 in Wei musou mode.
Zhang He: Clear 11 stages in Wei musou mode.
Zhang Liao: Clear Battle of Xia Pi in Chapter 3 of Wei musou mode.
Zhen Ji: Clear Chapter 3 in Wei musou mode.
Unlock: Dong Zhou's Musou Mode
Complete Lu Bu's Musou Mode one time.
Unlock: Lu Bu's Musou Mode
Clear any kingdom's Musou Mode.
Unlock: Nanman Musou Mode
Defeat Meng Hou in a duel in the "Nanman Campaign".
Unlock: Yuan Shao's Musou Mode
Clear Wei's Musou Mode at least one time.
Unlocking Dong Zhuo, Lü Bu, and Yuan Shao.
Complete these tasks in-game to unlock the following characters: