Maybe something like that..
Spoiler for don't read if you haven't finished the game:
1/3 tearsXluke hyperressonance accident // end of tartarus accident
4/6 choral castle // chesedonia
8/11 back to baticul // yulia city
12/15 asch becoming lead char // luke awaken
16/26 ...what happen next.
...of course i'm merely guessing they'll only use the BIG event of the game.
for instance: