Ionocidium was for a different topic (evasion). I just used her as example.

For Treasure Rally:
In each area, there are 4 lanes with a girl in each of them. Each lane has different rewards (manyu, dragons, gifts+ampules, forge spirits). For every Nazupon roll, the number on the ball determines how many steps a girl will take. You can choose to move any of the 4 girls after rolling. Somewhere before the end of each lane, there's a chest containing either the event girl or an upgrade of her. A number at the top of the lane will show how many steps exactly you need before that item. It will be gone from other lanes once a girl in a particular lane gets it.