|This battle will unlock the Hypothetical route for Wei's story. In order to gain access to it, you must complete all optional objectives in battles prior to this one on the stage select screen. Once you do, talk to Guo Jia in the camp before the battle begins.|
Start the battle off by clearing the enemy officers to the north of the main camp, of which there are a total of three. After that, Xu Shu will mention that the enemy's plan is to link the ships together and wants you to follow him to where the culprit is located. Do that and you'll find Pang Tong, so defeat him to continue.
Once that is over, you need to head to the indicated ship and wait until the enemy's surprise attack comes. This is led by Huang Gai and Han Dang and will light that ship ablaze, but defeating them will end that. After taking down those two, Cai Mao defects so head over to where he is. He doesn't seem to listen, so defeat him to make him rejoin Wei.
Board the ship to the south and once everyone gets on it, the ship will start moving to the eastern side of the map. Start clearing out all of the enemy officers as you make your way to the main camp. Note that Liu Bei and Sun Shangxiang appear to the south of the main camp, although they will chase after you. You should go to the altar and defeat Zhuge Liang, which is the first path to the west as you go north.
Continue fighting your way to the enemy's main camp, defeating any officers you come across on the way. When you get to the front gates, defeat Ding Feng, then go inside and defeat Sun Quan to finish the battle.