Talking C has become a popular entertainment nowadays, and they are all people who like this way of social interaction. But traveling through language C is indispensable, and as for saving the world and so on - naturally it is also a basic operation.
The woman who calls herself Gui Yue guides those who have obtained the Command Spell to summon heroic spirits, and leads the being who calls herself Ruler to launch a war against the invaders named "Beasts".
The people in the group who traveled through time were all selected trialists, and in the communication channel that was obtained along with the spirit base - the name "Zhongli" never lit up.
Or, in other words, something else happened during the unknown time gap that they could not understand.
Purpose: Let the people of Yokohama experience the "beauty" of the Holy Grail War