Diaochan

EX Weapon: Chain Whip
Weapon Name and Skills: Phoenix Spine - Frost: 10, Survival: 9, Enlightenment: 9, Jolt: 8
Stage: Eliminate Dong Zhuo
Requirements: Defeat Zhang Liao within 8 minutes of starting the battle.

Very difficult to obtain without one shotting every single officer. All officers must be defeated in less than 10 seconds. The main problem of this scenario is the lengthy dialogue. The second problem is the ambush laid on Lu Bu. The ambush is probably the most time consuming part. Trigger the ambush first by going straight to throne room after Lu Bu defects, then rush back to defeat the southern officer, by the time you defeat him, the northern officer will be very close by. Defeating the northern officer first will make the second officer poking Lu Bu, thus wasting precious time.

By one shotting every officer using Diaochans Musou 2, there will be around 20 seconds to defeat Zhang Liao.

If you find that you are cutting it too close you can save and reload abuse to skip the dialogue, granted it will take longer playtime wise.

Lu Bu

EX Weapon: Halberd
Weapon Name and Skills: Soulcrusher - Flash: 10, Induction: 9, Jolt: 9, Awareness
Stage: Xiapi Defensive Battle
Requirements: Rescue Song Xian, Hou Cheng, and Wei Xu, thus preventing their defection.

Rather straight forward weapon to get, you may want to use Red Hare if you feel the need to.

Dong Zhuo

EX Weapon: Bombs
Weapon Name and Skills: Demon Bomb - Venom: 10, Aggression (Musou damage): 9, Awareness, Thorns: 8
Stage: Chase at Hulao Gate
Requirements: Defeat Yuan Shao within 7 minutes of Luoyang erupting in flames without losing a single officer from Dong Zhuo's forces.

This can be a pretty time extensive weapon to get due to the amount of dialogue that happens, you will need to save all officers who are caught up in a battle to get Diaochans whereabouts to be able to leave Sishui Gate.

Yuan Shao

EX Weapon: Extension Blade
Weapon Name and Skills: Heaven's Reach - Venom: 10, Awe: 9, Aggression (Musou damage): 9, Aggression (Same Affinity = Attack up): 8
Stage: Skirmish at Guandu
Requirements: Prevent the withdrawal of Liu Bei and Zhang Fei while preventing Zhenji and Zhang He from defecting.

To prevent Liu Bei and Zhang Fei from withdrawing you will need to defeat Guan Yu at Baima. To prevent Zhenji from defecting you have to defeat Cao Pi at Yanjin. To prevent Zhang He from defecting you have to defeat Xiahou Yuan who will move to Zhang He's area.

Zhang Jiao

EX Weapon: Shaman Rod
Weapon Name and Skills: Heavenly Scepter - Thunder: 10, Frenzy: 9, Whirlwind: 9, Morass: 8
Stage: Yellow Turban Conflict
Requirements: Defeat Huangfu Song without losing a single Yellow Turban officer.

Very easy to obtain considering how powerful Zhang Jiao is by default. To ensure every officer survives, defeat Sun Jian, Cao Cao, and Liu Beis forces.

Meng Huo

EX Weapon: Gloves
Weapon Name and Skills: Shaman's Gloves - Venom: 10, Awe: 9, Jolt: 9, Explosive: 8
Stage: Rescue at Baidi Castle
Requirement: Defeat 3 of the following officers with a ballista within 8 minutes of starting the battle: Chen Jiao, Chen Wei, Cao Zhang, or Wang Shuang.

Easy to obtain despite time limit. These 4 officers will rush to the center area after you save everyone inside the Castle area. Lower their health, then get into a ballista and start firing at them.

Zhurong

EX weapon: Boomerang
Weapon Name and Skills: Heaven's Return - Flash: 10, Explosive: 9, Chain: 9, Flurry: 8
Stage: Nanzhong Rescue Mission
Requirement: After rescuing King Mulu save Meng Huo before King Mulu reappears.

You will want to save King Mulu last to give you the most time to save Meng Huo who will be in the center garrison. Meng Huos location will be known after the last officer is rescued.

Zuo Ci

EX weapon: Talisman Cards
Weapon Name and Skills: Heavenly Deck - Frost: 10, Frenzy: 9, Greed, Awe: 8
Stage: Phantoms of Xuchang
Requirement: Successfully place all 3 altars and defeat Sima Yi while keeping the altars up.

Make sure to defeat the messenger who will report to Cao Ren which will bolster the defenses as well as taking away the third altar spot. Pay attention to when Sima Yi starts talking, then take out the engineers as soon as they spawn in the reverse T-shaped intersection area.

Chen Gong

EX Weapon: Art of War Scroll
Stage: Capture of Puyang
Weapon Name and Skills: God's Decree Scroll - Thunder: 10, Recovery: 9, Uplift: 9, Induction: 8
Requirement: Ensure Tian Shi's fake letter succeeds within 9 minutes if starting the battle.

When the battle begins defeat every officer in Zhang Miaos way so he can convince Xu Si, Fan Yi & Wang Kai to help Lu Bus forces. Capture Puyang Castle first then make your way to Juan Castle, but wait for Xu Si to mention having Tian Shi join by making a forged letter to Cao Cao. After capturing Juan Castle defeat the reinforcements heading for it and see that the Engineer makes it safely out of the battle.

Lu Lingqi

EX Weapon: Crossed Pike
Stage: Assault on Xiapi
Weapon Name and Skills: Ultimate Collapse - Slash: 10, Agility, Enlightenment: 9, Resolve
Requirement: Defeat all 5 of Liu Bei's officers who are lured by the diversion before Liu Bei's forces climb down from Xiapi Castle's rampart.

Rather easy objective as they will all come for you as soon as the drawbridge goes down.