Dynasty at War: I Can Summon the Forces of Valoran

[Power fantasy, many beauties from ancient times and League of Legends, Warring States conquest, System, a high school student becomes emperor]

An accident sends Chen Tianyu and all his classmates, who are attending their vocational school graduation reunion, to another world. This continent is just like the Warring States period, with rival nations constantly at war.

Chen Tianyu and his classmates each become emperors, chancellors, or grand marshals in these countries.

Teachers who never got along, classmates who had feuded with him, and those so-called "little fairies" all reveal their true natures on this continent, directing every kind of scheme and trick against their classmates.

Unlucky Chen Tianyu gets off to a bad start: he transmigrates to the state of Qian, whose territory is only as large as Shanghai. The country is already in the middle of a civil war, and he almost hangs himself from a crooked tree on the back hill.

Just as Chen Tianyu is about to accept his fate, his personal System appears, instantly summoning troops from Noxus and Demacia to put down the rebellion. As a bonus, he adds Lux to his harem.

The System tells him that every time he conquers a country, its unique talents and beauties will appear. Now that Chen Tianyu knows the rules in advance, he keeps going further and further along the road to recruiting talent.

In the end, he unites the many states and stands firm against the arrival of the Holy Keisha and Grandpa Hua.