All weapons
Guan Ping - Chi Bi Retreat Battle - Defeat all the generals, then when the 2 reinforcements appear kill the general at the escape point.
Guan Yu - Battle of Fan Castle - Kill the gate and stronghold captain in under 5 minutes. Then kill Niu Jin and Le Jin and enter the castle to start the flood event.
Huang Zhong - Battle of Mt. Ding Jun - Kill Xiahou Yuan and Zhang He before Cao Cao arrives.
Jiang Wei - Battle of Wu Zhang Plains - Complete all events before the death of Kongming. Protect the wooden ox and then kill Zhang He and Xiahou Dun.
Liu Bei - Battle of Ru Nan - Meet up with Guan Yu and Zhao Yun then kill all officers except Cao Cao.
Ma Chao - Battle of Tong Gate - Cross the river at the start of the map and knock Cao Cao off his horse before he crosses to the opposite side from where he starts.
Pang Tong - Battle Of Nan Zhong - Kill the gate troops to get the bridge event. Seal the gate near Kongming and then wait for the Yue Ying Tank event. Ignore Meng Huo until he retreats. Protect the bridge captain and kill Wu Tugu to get an item report.
Wei Yan - Battle of Cheng Du - Complete all objectives and don't trigger the ambush. Keep all your allied generals alive.
Xing Cai - Battle Of Bai Dai - Let Xing Cai's health fall into the orange section so Liu Chan gives you a message about courage. Meet up with Liu Chan to trigger a cutscene and a morale increase. Then rescue your allies and head back to Ba Dai.
Yue Ying - Battle of Wu Zhang Plains - Defend the wooden ox for their entire journey.
Zhang Fei - Battle Of Chang Ban - Kill Xiahou Dun and his officers. Meet up with Zhao Yun and return to camp. Kill Xiahou En to get an item report.
Zhao Yun - Battle of Cheng Du - Move to the west gate and kill Liu Xun and the gate captain there. Then take the North gate in the base.
Zhuge Liang - Battle Of Tian Shui - Occupy An Ding and Nanan. Then release Xiahou Lin and a defection will be reported. Go near Tian Shui and Jiang Wei will try and return to the castle. Stop him by killing him and you'll get an item report.
Kingdom of Wei
Cao Cao - Battle of Xia Pi - Go to the water gate and kill Zhang Liao and then Gao Shun. The water event will happen and you'll be notified about an item which is the 4th weapon.
Cao Pi - Battle of Wu Zhang Plains - Secure the Supply lines and destroy all the Automatic Crossbows.
Cao Ren - Chi Bi Escape Battle - Kill Guan Yu, Liu Bei and their officers. When Sun Quan arrives kill him as well. This must be done while keeping all of your officers alive.
Dian Wei - Battle of Wan Castle - Meet with Cao Cao and then defeat Hu Che Er and Jia Xu. Then kill 10 troop leaders without letting any of them get past you.
Pang De - Battle of Mt. Ding Jun - Kill all officers except Liu Bei and Huang Zhong before he charges. After Huang Zhong has charged then kill him.
Sima Yi - Battle of Chen Cang - Control 3 of the weapons storage locations without losing control of the castle.
Xiahou Dun - Battle of Fan Castle - Kill Guan Ping to prevent the water attack.
Xiahou Yuan - Battle Of Mt. Jing Dun - When Huang Zhong charges, kill him and his officer.
Xu Huang - Battle of Fan Castle - Kill all officers in under 11 minutes.
Xu Zhu - Battle Of Tong Gate - Make Han Sui defect and then escort Cao Cao back to base.
Zhang He - Battle of Jie Ting - Surround Ma Su and then kill him when he says that he is retreating to the main camp.
Zhang Liao - Battle of Hei Fei - Kill 6 officers to get an event. Then keep killing generals until a second event happens. Then there'll be an item report.
Zhen Ji - Battle of He Fei - Kill Taishi Ci and destroy the siege ram. Go back to base to trigger an event. Wait for Cao Pi to appear then there'll be another event and you'll get an item report.
Kingdom of Wu
Da Qiao - Battle of Xia Kou - Clear out the boat before it leaves the docks and kill Gan Ning. You'll then get an item report, the 4th weapon.
Gan Ning - Battle of Xia Kou - Kill Ling Chao. Then you'll get an event where Ling Tong attacks Gan Ning. Kill Ling Tong and Ling Cao.
Huang Gai - Battle of Chi Bi - Set the ships on fire and then help Zhuge Liang to get the wind event, do not help Pang Tong though.
Ling Tong - Battle Of He Fei - Defeat Zhang Liao 4 times.
Lu Meng - Battle Of Yi Ling - Kill all gate captains in under 6 minutes.
Lu Xun - Battle of Bai Di - Go into the maze and successfully come out the other side. Once you've done that you must defeat Jiang Wei. Then Ma Chao will attack your base, defeat him to get an item report.
Sun Ce - Sun Ce Illusionary Battle - Kill fake Sun Ce(s) and Da Qiao then all of Gan Ji clones.
Sun Jian - Battle of Shi Shui Gate - Defeat Lu Bu in under 5 minutes.
Sun Shang Xiang - Battle Of Nan Zhong - Return to base when reinforcements arrive and kill all of the backup troops.
Sun Quan - Battle of Chi Bi - Kill Wang Lang then clear the bridge. Kill Cao Mao, clear the bridge again. Succeed in the sabotage and make sure Pang Tong succeeds as well. Help Huang Gai start the fire and help Zhuge Liang succeed in the wind prayer. Once they both succeed, you'll get an item report.
Taishi Ci - Battle of Wu Jun - Lure Sun Quan into the fort and defeat him before Zhou Tai arrives, then kill Zhou Tai.
Xiao Qiao - Battle of Jing Zhou - Prevent Sun Jian from being ambushed. Kill Huang Zu and then kill Zhang Hu, Jing Liang, Cao Mao and Lu Gong. Seal all strongholds and keep all allies alive, this will prevent reinforcements from arriving and you'll get an item report.
Zhou Tai - Battle Of Yi Ling - The fire event must happen while keeping all your generals alive. There'll be an item report.
Zhou Yu - Battle of Wu Territory - Kill Yan Baihu and Wang Lang.
Other Officers
Diao Chan - Battle Of Chang Shang - Help Lu Bu when he is ambushed and repel the attack.
Dong Zhou - Battle of Hu Lao Gate - Seal the gates by the castle and then kill every sub general.
Lu Bu - Battle of Chang Shang, Yuan Shao side - Get the event where Yuan Shao doesn't trust Lu Bu, then there'll be an ambush and Yuan Shao will choose not to rescuse you. There'll be a Diao Chan event, then kill Zhang Yan and wait until Yuan Shao trusts you. Then get 1000 kills. (KOs)
Meng Huo - Battle of Nan Zhong - Defeat all enemy officers without losing any of your own.
Yuan Shao - Battle Of Yi Zhou - Defeat all officers in under 11 minutes.
Zhang Jiao - Battle of Jing Zhou - Kill everyone in under 10 minutes.
Zhu Rong - Nanman Campaign - Have the Wu Tugu event occur and stop him from being killed. Then kill Wang Ping and Guan Xing.