OnActivated is an Event Dispatcher which I saw in the example: https://docs.unrealengine.com/latest/INT/Resources/ContentExamples/Blueprints_Advanced/2_5/index.html.
I don’t see why I should bind the event in the parent, because I just want to call the event dispatcher in my child blueprints. What I’m trying to do is have the player press a key to activate a powerup, there are a lot of powerup so I need a parent / child structure (I think), then I want to call an “Activate Powerup” function and at the same time be able to chose which powerup it should activate. I hope this clears things up.