The effect overview can be used to view or modify a list of projectile effects. This will either be the list of impact effects or the list of effects of an in-flight effect wave. If you have a single projectile effect that spawns magic crit particles, it should look like this:

On the left, there is a 'Back' button and an 'Add' button. Additionally, there is an 'Edit', 'Copy' and 'Delete' button for each projectile effect in the effect list you are viewing.