Delete actor from another actor behavior tree

I am new to unreal engine and am trying to make a simple attack behavior for one of my actors. Here is the behavior tree


Here is the attack task

And here is where i set the Enemy object to the black board in the controller event graph:
a
It is failing to cast to the Fly, I have tried some other ways but to no avail. What is the right way of doing this? I want the Fly to be destroyed after the animation (or during). Any help appreciated :slight_smile: