Sorry this thread is a bit old but I can help on understanding this “On Possessed” Node to anyone else having this issue. The on possessed node is called on Possession by any controller, including player controller OR AI controller. I was also having this issue until I realized that “Event Possessed” meant any controller. So Yes, the argument that the OP posted would be a correct way to fix this if you plan on having multiple controllers possess an AI, as that is also the plan in my current project. Here’s how I implemented this fix
This way you can still have an AIC auto possess a character or pawn if you would prefer that method