There are good guides at here, I would like to put my solution.
When you get BOW at Fortress Vimana,
1. go to left when ZEBEI was in a jail.
2. Curiously you can see ZEBEI at there, stay next to him.
3. spam your
4. the combo counter appears on top-right on your screen.
5. it pops when the counter stops.
And Indivisible has unique save data system. It maybe helps your trouble.
Check "Load Game" and move
to right, you can see bunch of your old save data.
If you're the all save point traveler, the best data is the 2nd of Fortress Vimana.
Hope it helps.