The Slacker Crown Prince's Nation-Saving System

Li Chengqian says he just wants to take it easy, but the System insists on forcing him to become a wise ruler:

[Ding! Host, save Li Shimin, who is on the brink of death. Reward: penicillin injection]

[Ding! Host, promote potato cultivation. Reward: hybrid rice technology]

[Ding! Host, prevent the Xuanwu Gate Incident. Reward: AK-47 blueprints]

Forced to complete missions under the System’s threats, Li Chengqian discovers that every reward is changing the fate of the Tang dynasty... And the System’s ultimate mission is to have him transmigrate through the dynasties with great ministers like Wei Zheng and Fang Xuanling, helping historical figures resolve the regrets that haunt them!