The protagonist's true form is that of a frail college student who can't lift a finger to help, and he gets dropped into the chaos at the end of the Sui dynasty. War breaks out everywhere, rebellions erupt, and the unlucky protagonist flees for his life. Luckily, he has a life-simulation game System. The protagonist summons two little characters, one civilian and one military...
The protagonist and his two little characters, one civilian and one military, flee for their lives together.
The little characters need to raise their skill points before they can become a talented scholar and a skilled general. The protagonist stays holed up in a single-player room that can be refreshed and rewound each day, letting the two characters grind skill points. The scholar character boosts his strategic skills by reading the protagonist's steamy fantasy novels, while the military character trains his martial skills by cooking and doing laundry for the protagonist every day.
At last, both characters have enough skill points. The protagonist sends them out to make their mark, thinking that once they achieve success and fame, he'll rise along with them and be able to eat three buns in one meal.
The little characters remember the protagonist saying they should follow a lord surnamed Li, whose name has two characters, because that guy will later found the Tang dynasty. The scholar character thinks: What was his name again...?
That's the one, Li...
Li Mi!
The Sui dynasty is about to fall, and the Tang dynasty is about to rise.
The scholar character has picked a rival of Emperor Gaozong of Tang.
The military character has ended up serving the last emperor of the Sui dynasty.
Protagonist: .
That's not right. The protagonist just wants to get to the capital and lie down.
Luckily, in the chaos at the end of the Sui dynasty, it was normal for strategists and generals to switch sides again and again. Even Wei Zheng changed allegiance several times without it hurting his resume. The protagonist tells the little characters to find a way into the Tang camp.
The two little characters nod. The military character tries to get captured by Li Yuan and his people, but accidentally becomes a mighty general who charges in and out of Tang strongholds seven times. The young Li Shimin just can't capture him. Instead, the military character seizes cities and conquers territory.
Military character: Trembling in fear.
Li Shimin: It would be a great regret if this general did not serve me!
The scholar character tries to make his side lose, using all sorts of mystical wind-reading methods to deploy the troops. Instead, he accidentally starts calling the wind and gets every prediction right.
Scholar character: Sweating profusely.
Li Shimin: Does our army have anyone who can foretell events with such uncanny accuracy? Heaven itself must be helping us!
The scholar and military characters are frantic. No matter what they do, they can't get captured by the Tang forces. They're still trying to figure out how to get themselves over there when Li Shimin finds their weak spot and captures the frail protagonist!
The protagonist, holed up at home: Huh?? What's going on??
Scholar character (guilty): He captured you to force me to become one of the twenty-four meritorious ministers in the Lingyan Pavilion.
Military character (breaking out in a cold sweat): He captured you to force me to become a founding marshal and great general.
Protagonist: Huh? What about me?
Little characters: You became a Shangzhuguo.
Protagonist: .
Many years later, the protagonist, whose appearance has never aged, is about to become emperor.
The others ask him: How did you become a prince of the Tang dynasty with a different surname???
Protagonist: ...I don't know either.
Protagonist: I woke up this morning, and my little characters, who'd become an empress, a minister, a general, a wealthy merchant... had just draped the imperial robe over me.
↑That's roughly the kind of story this is. It covers the end of the Sui dynasty through the Reign of Zhenguan.
Theme: Go with the flow of history